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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 bool check_dr_size(size_t size, size_t *tot_size)
93{
94 /* We must catch any near-SIZE_MAX cases that could overflow. */
95 if (unlikely(check_add_overflow(sizeof(struct devres),
96 size, tot_size)))
97 return false;
98
99 return true;
100}
101
102static __always_inline struct devres * alloc_dr(dr_release_t release,
103 size_t size, gfp_t gfp, int nid)
104{
105 size_t tot_size;
106 struct devres *dr;
107
108 if (!check_dr_size(size, &tot_size))
109 return NULL;
110
111 dr = kmalloc_node_track_caller(tot_size, gfp, nid);
112 if (unlikely(!dr))
113 return NULL;
114
115 memset(dr, 0, offsetof(struct devres, data));
116
117 INIT_LIST_HEAD(&dr->node.entry);
118 dr->node.release = release;
119 return dr;
120}
121
122static void add_dr(struct device *dev, struct devres_node *node)
123{
124 devres_log(dev, node, "ADD");
125 BUG_ON(!list_empty(&node->entry));
126 list_add_tail(&node->entry, &dev->devres_head);
127}
128
129#ifdef CONFIG_DEBUG_DEVRES
130void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
131 const char *name)
132{
133 struct devres *dr;
134
135 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
136 if (unlikely(!dr))
137 return NULL;
138 set_node_dbginfo(&dr->node, name, size);
139 return dr->data;
140}
141EXPORT_SYMBOL_GPL(__devres_alloc_node);
142#else
143/**
144 * devres_alloc - Allocate device resource data
145 * @release: Release function devres will be associated with
146 * @size: Allocation size
147 * @gfp: Allocation flags
148 * @nid: NUMA node
149 *
150 * Allocate devres of @size bytes. The allocated area is zeroed, then
151 * associated with @release. The returned pointer can be passed to
152 * other devres_*() functions.
153 *
154 * RETURNS:
155 * Pointer to allocated devres on success, NULL on failure.
156 */
157void * devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid)
158{
159 struct devres *dr;
160
161 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
162 if (unlikely(!dr))
163 return NULL;
164 return dr->data;
165}
166EXPORT_SYMBOL_GPL(devres_alloc_node);
167#endif
168
169/**
170 * devres_for_each_res - Resource iterator
171 * @dev: Device to iterate resource from
172 * @release: Look for resources associated with this release function
173 * @match: Match function (optional)
174 * @match_data: Data for the match function
175 * @fn: Function to be called for each matched resource.
176 * @data: Data for @fn, the 3rd parameter of @fn
177 *
178 * Call @fn for each devres of @dev which is associated with @release
179 * and for which @match returns 1.
180 *
181 * RETURNS:
182 * void
183 */
184void devres_for_each_res(struct device *dev, dr_release_t release,
185 dr_match_t match, void *match_data,
186 void (*fn)(struct device *, void *, void *),
187 void *data)
188{
189 struct devres_node *node;
190 struct devres_node *tmp;
191 unsigned long flags;
192
193 if (!fn)
194 return;
195
196 spin_lock_irqsave(&dev->devres_lock, flags);
197 list_for_each_entry_safe_reverse(node, tmp,
198 &dev->devres_head, entry) {
199 struct devres *dr = container_of(node, struct devres, node);
200
201 if (node->release != release)
202 continue;
203 if (match && !match(dev, dr->data, match_data))
204 continue;
205 fn(dev, dr->data, data);
206 }
207 spin_unlock_irqrestore(&dev->devres_lock, flags);
208}
209EXPORT_SYMBOL_GPL(devres_for_each_res);
210
211/**
212 * devres_free - Free device resource data
213 * @res: Pointer to devres data to free
214 *
215 * Free devres created with devres_alloc().
216 */
217void devres_free(void *res)
218{
219 if (res) {
220 struct devres *dr = container_of(res, struct devres, data);
221
222 BUG_ON(!list_empty(&dr->node.entry));
223 kfree(dr);
224 }
225}
226EXPORT_SYMBOL_GPL(devres_free);
227
228/**
229 * devres_add - Register device resource
230 * @dev: Device to add resource to
231 * @res: Resource to register
232 *
233 * Register devres @res to @dev. @res should have been allocated
234 * using devres_alloc(). On driver detach, the associated release
235 * function will be invoked and devres will be freed automatically.
236 */
237void devres_add(struct device *dev, void *res)
238{
239 struct devres *dr = container_of(res, struct devres, data);
240 unsigned long flags;
241
242 spin_lock_irqsave(&dev->devres_lock, flags);
243 add_dr(dev, &dr->node);
244 spin_unlock_irqrestore(&dev->devres_lock, flags);
245}
246EXPORT_SYMBOL_GPL(devres_add);
247
248static struct devres *find_dr(struct device *dev, dr_release_t release,
249 dr_match_t match, void *match_data)
250{
251 struct devres_node *node;
252
253 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
254 struct devres *dr = container_of(node, struct devres, node);
255
256 if (node->release != release)
257 continue;
258 if (match && !match(dev, dr->data, match_data))
259 continue;
260 return dr;
261 }
262
263 return NULL;
264}
265
266/**
267 * devres_find - Find device resource
268 * @dev: Device to lookup resource from
269 * @release: Look for resources associated with this release function
270 * @match: Match function (optional)
271 * @match_data: Data for the match function
272 *
273 * Find the latest devres of @dev which is associated with @release
274 * and for which @match returns 1. If @match is NULL, it's considered
275 * to match all.
276 *
277 * RETURNS:
278 * Pointer to found devres, NULL if not found.
279 */
280void * devres_find(struct device *dev, dr_release_t release,
281 dr_match_t match, void *match_data)
282{
283 struct devres *dr;
284 unsigned long flags;
285
286 spin_lock_irqsave(&dev->devres_lock, flags);
287 dr = find_dr(dev, release, match, match_data);
288 spin_unlock_irqrestore(&dev->devres_lock, flags);
289
290 if (dr)
291 return dr->data;
292 return NULL;
293}
294EXPORT_SYMBOL_GPL(devres_find);
295
296/**
297 * devres_get - Find devres, if non-existent, add one atomically
298 * @dev: Device to lookup or add devres for
299 * @new_res: Pointer to new initialized devres to add if not found
300 * @match: Match function (optional)
301 * @match_data: Data for the match function
302 *
303 * Find the latest devres of @dev which has the same release function
304 * as @new_res and for which @match return 1. If found, @new_res is
305 * freed; otherwise, @new_res is added atomically.
306 *
307 * RETURNS:
308 * Pointer to found or added devres.
309 */
310void * devres_get(struct device *dev, void *new_res,
311 dr_match_t match, void *match_data)
312{
313 struct devres *new_dr = container_of(new_res, struct devres, data);
314 struct devres *dr;
315 unsigned long flags;
316
317 spin_lock_irqsave(&dev->devres_lock, flags);
318 dr = find_dr(dev, new_dr->node.release, match, match_data);
319 if (!dr) {
320 add_dr(dev, &new_dr->node);
321 dr = new_dr;
322 new_res = NULL;
323 }
324 spin_unlock_irqrestore(&dev->devres_lock, flags);
325 devres_free(new_res);
326
327 return dr->data;
328}
329EXPORT_SYMBOL_GPL(devres_get);
330
331/**
332 * devres_remove - Find a device resource and remove it
333 * @dev: Device to find resource from
334 * @release: Look for resources associated with this release function
335 * @match: Match function (optional)
336 * @match_data: Data for the match function
337 *
338 * Find the latest devres of @dev associated with @release and for
339 * which @match returns 1. If @match is NULL, it's considered to
340 * match all. If found, the resource is removed atomically and
341 * returned.
342 *
343 * RETURNS:
344 * Pointer to removed devres on success, NULL if not found.
345 */
346void * devres_remove(struct device *dev, dr_release_t release,
347 dr_match_t match, void *match_data)
348{
349 struct devres *dr;
350 unsigned long flags;
351
352 spin_lock_irqsave(&dev->devres_lock, flags);
353 dr = find_dr(dev, release, match, match_data);
354 if (dr) {
355 list_del_init(&dr->node.entry);
356 devres_log(dev, &dr->node, "REM");
357 }
358 spin_unlock_irqrestore(&dev->devres_lock, flags);
359
360 if (dr)
361 return dr->data;
362 return NULL;
363}
364EXPORT_SYMBOL_GPL(devres_remove);
365
366/**
367 * devres_destroy - Find a device resource and destroy it
368 * @dev: Device to find resource from
369 * @release: Look for resources associated with this release function
370 * @match: Match function (optional)
371 * @match_data: Data for the match function
372 *
373 * Find the latest devres of @dev associated with @release and for
374 * which @match returns 1. If @match is NULL, it's considered to
375 * match all. If found, the resource is removed atomically and freed.
376 *
377 * Note that the release function for the resource will not be called,
378 * only the devres-allocated data will be freed. The caller becomes
379 * responsible for freeing any other data.
380 *
381 * RETURNS:
382 * 0 if devres is found and freed, -ENOENT if not found.
383 */
384int devres_destroy(struct device *dev, dr_release_t release,
385 dr_match_t match, void *match_data)
386{
387 void *res;
388
389 res = devres_remove(dev, release, match, match_data);
390 if (unlikely(!res))
391 return -ENOENT;
392
393 devres_free(res);
394 return 0;
395}
396EXPORT_SYMBOL_GPL(devres_destroy);
397
398
399/**
400 * devres_release - Find a device resource and destroy it, calling release
401 * @dev: Device to find resource from
402 * @release: Look for resources associated with this release function
403 * @match: Match function (optional)
404 * @match_data: Data for the match function
405 *
406 * Find the latest devres of @dev associated with @release and for
407 * which @match returns 1. If @match is NULL, it's considered to
408 * match all. If found, the resource is removed atomically, the
409 * release function called and the resource freed.
410 *
411 * RETURNS:
412 * 0 if devres is found and freed, -ENOENT if not found.
413 */
414int devres_release(struct device *dev, dr_release_t release,
415 dr_match_t match, void *match_data)
416{
417 void *res;
418
419 res = devres_remove(dev, release, match, match_data);
420 if (unlikely(!res))
421 return -ENOENT;
422
423 (*release)(dev, res);
424 devres_free(res);
425 return 0;
426}
427EXPORT_SYMBOL_GPL(devres_release);
428
429static int remove_nodes(struct device *dev,
430 struct list_head *first, struct list_head *end,
431 struct list_head *todo)
432{
433 int cnt = 0, nr_groups = 0;
434 struct list_head *cur;
435
436 /* First pass - move normal devres entries to @todo and clear
437 * devres_group colors.
438 */
439 cur = first;
440 while (cur != end) {
441 struct devres_node *node;
442 struct devres_group *grp;
443
444 node = list_entry(cur, struct devres_node, entry);
445 cur = cur->next;
446
447 grp = node_to_group(node);
448 if (grp) {
449 /* clear color of group markers in the first pass */
450 grp->color = 0;
451 nr_groups++;
452 } else {
453 /* regular devres entry */
454 if (&node->entry == first)
455 first = first->next;
456 list_move_tail(&node->entry, todo);
457 cnt++;
458 }
459 }
460
461 if (!nr_groups)
462 return cnt;
463
464 /* Second pass - Scan groups and color them. A group gets
465 * color value of two iff the group is wholly contained in
466 * [cur, end). That is, for a closed group, both opening and
467 * closing markers should be in the range, while just the
468 * opening marker is enough for an open group.
469 */
470 cur = first;
471 while (cur != end) {
472 struct devres_node *node;
473 struct devres_group *grp;
474
475 node = list_entry(cur, struct devres_node, entry);
476 cur = cur->next;
477
478 grp = node_to_group(node);
479 BUG_ON(!grp || list_empty(&grp->node[0].entry));
480
481 grp->color++;
482 if (list_empty(&grp->node[1].entry))
483 grp->color++;
484
485 BUG_ON(grp->color <= 0 || grp->color > 2);
486 if (grp->color == 2) {
487 /* No need to update cur or end. The removed
488 * nodes are always before both.
489 */
490 list_move_tail(&grp->node[0].entry, todo);
491 list_del_init(&grp->node[1].entry);
492 }
493 }
494
495 return cnt;
496}
497
498static int release_nodes(struct device *dev, struct list_head *first,
499 struct list_head *end, unsigned long flags)
500 __releases(&dev->devres_lock)
501{
502 LIST_HEAD(todo);
503 int cnt;
504 struct devres *dr, *tmp;
505
506 cnt = remove_nodes(dev, first, end, &todo);
507
508 spin_unlock_irqrestore(&dev->devres_lock, flags);
509
510 /* Release. Note that both devres and devres_group are
511 * handled as devres in the following loop. This is safe.
512 */
513 list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
514 devres_log(dev, &dr->node, "REL");
515 dr->node.release(dev, dr->data);
516 kfree(dr);
517 }
518
519 return cnt;
520}
521
522/**
523 * devres_release_all - Release all managed resources
524 * @dev: Device to release resources for
525 *
526 * Release all resources associated with @dev. This function is
527 * called on driver detach.
528 */
529int devres_release_all(struct device *dev)
530{
531 unsigned long flags;
532
533 /* Looks like an uninitialized device structure */
534 if (WARN_ON(dev->devres_head.next == NULL))
535 return -ENODEV;
536 spin_lock_irqsave(&dev->devres_lock, flags);
537 return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
538 flags);
539}
540
541/**
542 * devres_open_group - Open a new devres group
543 * @dev: Device to open devres group for
544 * @id: Separator ID
545 * @gfp: Allocation flags
546 *
547 * Open a new devres group for @dev with @id. For @id, using a
548 * pointer to an object which won't be used for another group is
549 * recommended. If @id is NULL, address-wise unique ID is created.
550 *
551 * RETURNS:
552 * ID of the new group, NULL on failure.
553 */
554void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
555{
556 struct devres_group *grp;
557 unsigned long flags;
558
559 grp = kmalloc(sizeof(*grp), gfp);
560 if (unlikely(!grp))
561 return NULL;
562
563 grp->node[0].release = &group_open_release;
564 grp->node[1].release = &group_close_release;
565 INIT_LIST_HEAD(&grp->node[0].entry);
566 INIT_LIST_HEAD(&grp->node[1].entry);
567 set_node_dbginfo(&grp->node[0], "grp<", 0);
568 set_node_dbginfo(&grp->node[1], "grp>", 0);
569 grp->id = grp;
570 if (id)
571 grp->id = id;
572
573 spin_lock_irqsave(&dev->devres_lock, flags);
574 add_dr(dev, &grp->node[0]);
575 spin_unlock_irqrestore(&dev->devres_lock, flags);
576 return grp->id;
577}
578EXPORT_SYMBOL_GPL(devres_open_group);
579
580/* Find devres group with ID @id. If @id is NULL, look for the latest. */
581static struct devres_group * find_group(struct device *dev, void *id)
582{
583 struct devres_node *node;
584
585 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
586 struct devres_group *grp;
587
588 if (node->release != &group_open_release)
589 continue;
590
591 grp = container_of(node, struct devres_group, node[0]);
592
593 if (id) {
594 if (grp->id == id)
595 return grp;
596 } else if (list_empty(&grp->node[1].entry))
597 return grp;
598 }
599
600 return NULL;
601}
602
603/**
604 * devres_close_group - Close a devres group
605 * @dev: Device to close devres group for
606 * @id: ID of target group, can be NULL
607 *
608 * Close the group identified by @id. If @id is NULL, the latest open
609 * group is selected.
610 */
611void devres_close_group(struct device *dev, void *id)
612{
613 struct devres_group *grp;
614 unsigned long flags;
615
616 spin_lock_irqsave(&dev->devres_lock, flags);
617
618 grp = find_group(dev, id);
619 if (grp)
620 add_dr(dev, &grp->node[1]);
621 else
622 WARN_ON(1);
623
624 spin_unlock_irqrestore(&dev->devres_lock, flags);
625}
626EXPORT_SYMBOL_GPL(devres_close_group);
627
628/**
629 * devres_remove_group - Remove a devres group
630 * @dev: Device to remove group for
631 * @id: ID of target group, can be NULL
632 *
633 * Remove the group identified by @id. If @id is NULL, the latest
634 * open group is selected. Note that removing a group doesn't affect
635 * any other resources.
636 */
637void devres_remove_group(struct device *dev, void *id)
638{
639 struct devres_group *grp;
640 unsigned long flags;
641
642 spin_lock_irqsave(&dev->devres_lock, flags);
643
644 grp = find_group(dev, id);
645 if (grp) {
646 list_del_init(&grp->node[0].entry);
647 list_del_init(&grp->node[1].entry);
648 devres_log(dev, &grp->node[0], "REM");
649 } else
650 WARN_ON(1);
651
652 spin_unlock_irqrestore(&dev->devres_lock, flags);
653
654 kfree(grp);
655}
656EXPORT_SYMBOL_GPL(devres_remove_group);
657
658/**
659 * devres_release_group - Release resources in a devres group
660 * @dev: Device to release group for
661 * @id: ID of target group, can be NULL
662 *
663 * Release all resources in the group identified by @id. If @id is
664 * NULL, the latest open group is selected. The selected group and
665 * groups properly nested inside the selected group are removed.
666 *
667 * RETURNS:
668 * The number of released non-group resources.
669 */
670int devres_release_group(struct device *dev, void *id)
671{
672 struct devres_group *grp;
673 unsigned long flags;
674 int cnt = 0;
675
676 spin_lock_irqsave(&dev->devres_lock, flags);
677
678 grp = find_group(dev, id);
679 if (grp) {
680 struct list_head *first = &grp->node[0].entry;
681 struct list_head *end = &dev->devres_head;
682
683 if (!list_empty(&grp->node[1].entry))
684 end = grp->node[1].entry.next;
685
686 cnt = release_nodes(dev, first, end, flags);
687 } else {
688 WARN_ON(1);
689 spin_unlock_irqrestore(&dev->devres_lock, flags);
690 }
691
692 return cnt;
693}
694EXPORT_SYMBOL_GPL(devres_release_group);
695
696/*
697 * Custom devres actions allow inserting a simple function call
698 * into the teadown sequence.
699 */
700
701struct action_devres {
702 void *data;
703 void (*action)(void *);
704};
705
706static int devm_action_match(struct device *dev, void *res, void *p)
707{
708 struct action_devres *devres = res;
709 struct action_devres *target = p;
710
711 return devres->action == target->action &&
712 devres->data == target->data;
713}
714
715static void devm_action_release(struct device *dev, void *res)
716{
717 struct action_devres *devres = res;
718
719 devres->action(devres->data);
720}
721
722/**
723 * devm_add_action() - add a custom action to list of managed resources
724 * @dev: Device that owns the action
725 * @action: Function that should be called
726 * @data: Pointer to data passed to @action implementation
727 *
728 * This adds a custom action to the list of managed resources so that
729 * it gets executed as part of standard resource unwinding.
730 */
731int devm_add_action(struct device *dev, void (*action)(void *), void *data)
732{
733 struct action_devres *devres;
734
735 devres = devres_alloc(devm_action_release,
736 sizeof(struct action_devres), GFP_KERNEL);
737 if (!devres)
738 return -ENOMEM;
739
740 devres->data = data;
741 devres->action = action;
742
743 devres_add(dev, devres);
744 return 0;
745}
746EXPORT_SYMBOL_GPL(devm_add_action);
747
748/**
749 * devm_remove_action() - removes previously added custom action
750 * @dev: Device that owns the action
751 * @action: Function implementing the action
752 * @data: Pointer to data passed to @action implementation
753 *
754 * Removes instance of @action previously added by devm_add_action().
755 * Both action and data should match one of the existing entries.
756 */
757void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
758{
759 struct action_devres devres = {
760 .data = data,
761 .action = action,
762 };
763
764 WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
765 &devres));
766}
767EXPORT_SYMBOL_GPL(devm_remove_action);
768
769/**
770 * devm_release_action() - release previously added custom action
771 * @dev: Device that owns the action
772 * @action: Function implementing the action
773 * @data: Pointer to data passed to @action implementation
774 *
775 * Releases and removes instance of @action previously added by
776 * devm_add_action(). Both action and data should match one of the
777 * existing entries.
778 */
779void devm_release_action(struct device *dev, void (*action)(void *), void *data)
780{
781 struct action_devres devres = {
782 .data = data,
783 .action = action,
784 };
785
786 WARN_ON(devres_release(dev, devm_action_release, devm_action_match,
787 &devres));
788
789}
790EXPORT_SYMBOL_GPL(devm_release_action);
791
792/*
793 * Managed kmalloc/kfree
794 */
795static void devm_kmalloc_release(struct device *dev, void *res)
796{
797 /* noop */
798}
799
800static int devm_kmalloc_match(struct device *dev, void *res, void *data)
801{
802 return res == data;
803}
804
805/**
806 * devm_kmalloc - Resource-managed kmalloc
807 * @dev: Device to allocate memory for
808 * @size: Allocation size
809 * @gfp: Allocation gfp flags
810 *
811 * Managed kmalloc. Memory allocated with this function is
812 * automatically freed on driver detach. Like all other devres
813 * resources, guaranteed alignment is unsigned long long.
814 *
815 * RETURNS:
816 * Pointer to allocated memory on success, NULL on failure.
817 */
818void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
819{
820 struct devres *dr;
821
822 if (unlikely(!size))
823 return ZERO_SIZE_PTR;
824
825 /* use raw alloc_dr for kmalloc caller tracing */
826 dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
827 if (unlikely(!dr))
828 return NULL;
829
830 /*
831 * This is named devm_kzalloc_release for historical reasons
832 * The initial implementation did not support kmalloc, only kzalloc
833 */
834 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
835 devres_add(dev, dr->data);
836 return dr->data;
837}
838EXPORT_SYMBOL_GPL(devm_kmalloc);
839
840/**
841 * devm_kstrdup - Allocate resource managed space and
842 * copy an existing string into that.
843 * @dev: Device to allocate memory for
844 * @s: the string to duplicate
845 * @gfp: the GFP mask used in the devm_kmalloc() call when
846 * allocating memory
847 * RETURNS:
848 * Pointer to allocated string on success, NULL on failure.
849 */
850char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
851{
852 size_t size;
853 char *buf;
854
855 if (!s)
856 return NULL;
857
858 size = strlen(s) + 1;
859 buf = devm_kmalloc(dev, size, gfp);
860 if (buf)
861 memcpy(buf, s, size);
862 return buf;
863}
864EXPORT_SYMBOL_GPL(devm_kstrdup);
865
866/**
867 * devm_kstrdup_const - resource managed conditional string duplication
868 * @dev: device for which to duplicate the string
869 * @s: the string to duplicate
870 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
871 *
872 * Strings allocated by devm_kstrdup_const will be automatically freed when
873 * the associated device is detached.
874 *
875 * RETURNS:
876 * Source string if it is in .rodata section otherwise it falls back to
877 * devm_kstrdup.
878 */
879const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
880{
881 if (is_kernel_rodata((unsigned long)s))
882 return s;
883
884 return devm_kstrdup(dev, s, gfp);
885}
886EXPORT_SYMBOL_GPL(devm_kstrdup_const);
887
888/**
889 * devm_kvasprintf - Allocate resource managed space and format a string
890 * into that.
891 * @dev: Device to allocate memory for
892 * @gfp: the GFP mask used in the devm_kmalloc() call when
893 * allocating memory
894 * @fmt: The printf()-style format string
895 * @ap: Arguments for the format string
896 * RETURNS:
897 * Pointer to allocated string on success, NULL on failure.
898 */
899char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
900 va_list ap)
901{
902 unsigned int len;
903 char *p;
904 va_list aq;
905
906 va_copy(aq, ap);
907 len = vsnprintf(NULL, 0, fmt, aq);
908 va_end(aq);
909
910 p = devm_kmalloc(dev, len+1, gfp);
911 if (!p)
912 return NULL;
913
914 vsnprintf(p, len+1, fmt, ap);
915
916 return p;
917}
918EXPORT_SYMBOL(devm_kvasprintf);
919
920/**
921 * devm_kasprintf - Allocate resource managed space and format a string
922 * into that.
923 * @dev: Device to allocate memory for
924 * @gfp: the GFP mask used in the devm_kmalloc() call when
925 * allocating memory
926 * @fmt: The printf()-style format string
927 * @...: Arguments for the format string
928 * RETURNS:
929 * Pointer to allocated string on success, NULL on failure.
930 */
931char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
932{
933 va_list ap;
934 char *p;
935
936 va_start(ap, fmt);
937 p = devm_kvasprintf(dev, gfp, fmt, ap);
938 va_end(ap);
939
940 return p;
941}
942EXPORT_SYMBOL_GPL(devm_kasprintf);
943
944/**
945 * devm_kfree - Resource-managed kfree
946 * @dev: Device this memory belongs to
947 * @p: Memory to free
948 *
949 * Free memory allocated with devm_kmalloc().
950 */
951void devm_kfree(struct device *dev, const void *p)
952{
953 int rc;
954
955 /*
956 * Special cases: pointer to a string in .rodata returned by
957 * devm_kstrdup_const() or NULL/ZERO ptr.
958 */
959 if (unlikely(is_kernel_rodata((unsigned long)p) || ZERO_OR_NULL_PTR(p)))
960 return;
961
962 rc = devres_destroy(dev, devm_kmalloc_release,
963 devm_kmalloc_match, (void *)p);
964 WARN_ON(rc);
965}
966EXPORT_SYMBOL_GPL(devm_kfree);
967
968/**
969 * devm_kmemdup - Resource-managed kmemdup
970 * @dev: Device this memory belongs to
971 * @src: Memory region to duplicate
972 * @len: Memory region length
973 * @gfp: GFP mask to use
974 *
975 * Duplicate region of a memory using resource managed kmalloc
976 */
977void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
978{
979 void *p;
980
981 p = devm_kmalloc(dev, len, gfp);
982 if (p)
983 memcpy(p, src, len);
984
985 return p;
986}
987EXPORT_SYMBOL_GPL(devm_kmemdup);
988
989struct pages_devres {
990 unsigned long addr;
991 unsigned int order;
992};
993
994static int devm_pages_match(struct device *dev, void *res, void *p)
995{
996 struct pages_devres *devres = res;
997 struct pages_devres *target = p;
998
999 return devres->addr == target->addr;
1000}
1001
1002static void devm_pages_release(struct device *dev, void *res)
1003{
1004 struct pages_devres *devres = res;
1005
1006 free_pages(devres->addr, devres->order);
1007}
1008
1009/**
1010 * devm_get_free_pages - Resource-managed __get_free_pages
1011 * @dev: Device to allocate memory for
1012 * @gfp_mask: Allocation gfp flags
1013 * @order: Allocation size is (1 << order) pages
1014 *
1015 * Managed get_free_pages. Memory allocated with this function is
1016 * automatically freed on driver detach.
1017 *
1018 * RETURNS:
1019 * Address of allocated memory on success, 0 on failure.
1020 */
1021
1022unsigned long devm_get_free_pages(struct device *dev,
1023 gfp_t gfp_mask, unsigned int order)
1024{
1025 struct pages_devres *devres;
1026 unsigned long addr;
1027
1028 addr = __get_free_pages(gfp_mask, order);
1029
1030 if (unlikely(!addr))
1031 return 0;
1032
1033 devres = devres_alloc(devm_pages_release,
1034 sizeof(struct pages_devres), GFP_KERNEL);
1035 if (unlikely(!devres)) {
1036 free_pages(addr, order);
1037 return 0;
1038 }
1039
1040 devres->addr = addr;
1041 devres->order = order;
1042
1043 devres_add(dev, devres);
1044 return addr;
1045}
1046EXPORT_SYMBOL_GPL(devm_get_free_pages);
1047
1048/**
1049 * devm_free_pages - Resource-managed free_pages
1050 * @dev: Device this memory belongs to
1051 * @addr: Memory to free
1052 *
1053 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
1054 * there is no need to supply the @order.
1055 */
1056void devm_free_pages(struct device *dev, unsigned long addr)
1057{
1058 struct pages_devres devres = { .addr = addr };
1059
1060 WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
1061 &devres));
1062}
1063EXPORT_SYMBOL_GPL(devm_free_pages);
1064
1065static void devm_percpu_release(struct device *dev, void *pdata)
1066{
1067 void __percpu *p;
1068
1069 p = *(void __percpu **)pdata;
1070 free_percpu(p);
1071}
1072
1073static int devm_percpu_match(struct device *dev, void *data, void *p)
1074{
1075 struct devres *devr = container_of(data, struct devres, data);
1076
1077 return *(void **)devr->data == p;
1078}
1079
1080/**
1081 * __devm_alloc_percpu - Resource-managed alloc_percpu
1082 * @dev: Device to allocate per-cpu memory for
1083 * @size: Size of per-cpu memory to allocate
1084 * @align: Alignment of per-cpu memory to allocate
1085 *
1086 * Managed alloc_percpu. Per-cpu memory allocated with this function is
1087 * automatically freed on driver detach.
1088 *
1089 * RETURNS:
1090 * Pointer to allocated memory on success, NULL on failure.
1091 */
1092void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1093 size_t align)
1094{
1095 void *p;
1096 void __percpu *pcpu;
1097
1098 pcpu = __alloc_percpu(size, align);
1099 if (!pcpu)
1100 return NULL;
1101
1102 p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1103 if (!p) {
1104 free_percpu(pcpu);
1105 return NULL;
1106 }
1107
1108 *(void __percpu **)p = pcpu;
1109
1110 devres_add(dev, p);
1111
1112 return pcpu;
1113}
1114EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1115
1116/**
1117 * devm_free_percpu - Resource-managed free_percpu
1118 * @dev: Device this memory belongs to
1119 * @pdata: Per-cpu memory to free
1120 *
1121 * Free memory allocated with devm_alloc_percpu().
1122 */
1123void devm_free_percpu(struct device *dev, void __percpu *pdata)
1124{
1125 WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
1126 (void *)pdata));
1127}
1128EXPORT_SYMBOL_GPL(devm_free_percpu);
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_DMA_MINALIGN for data[] which will force the same
33 * alignment for struct devres when allocated by kmalloc().
34 */
35 u8 __aligned(ARCH_DMA_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 grp->color = 0;
571
572 spin_lock_irqsave(&dev->devres_lock, flags);
573 add_dr(dev, &grp->node[0]);
574 spin_unlock_irqrestore(&dev->devres_lock, flags);
575 return grp->id;
576}
577EXPORT_SYMBOL_GPL(devres_open_group);
578
579/* Find devres group with ID @id. If @id is NULL, look for the latest. */
580static struct devres_group *find_group(struct device *dev, void *id)
581{
582 struct devres_node *node;
583
584 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
585 struct devres_group *grp;
586
587 if (node->release != &group_open_release)
588 continue;
589
590 grp = container_of(node, struct devres_group, node[0]);
591
592 if (id) {
593 if (grp->id == id)
594 return grp;
595 } else if (list_empty(&grp->node[1].entry))
596 return grp;
597 }
598
599 return NULL;
600}
601
602/**
603 * devres_close_group - Close a devres group
604 * @dev: Device to close devres group for
605 * @id: ID of target group, can be NULL
606 *
607 * Close the group identified by @id. If @id is NULL, the latest open
608 * group is selected.
609 */
610void devres_close_group(struct device *dev, void *id)
611{
612 struct devres_group *grp;
613 unsigned long flags;
614
615 spin_lock_irqsave(&dev->devres_lock, flags);
616
617 grp = find_group(dev, id);
618 if (grp)
619 add_dr(dev, &grp->node[1]);
620 else
621 WARN_ON(1);
622
623 spin_unlock_irqrestore(&dev->devres_lock, flags);
624}
625EXPORT_SYMBOL_GPL(devres_close_group);
626
627/**
628 * devres_remove_group - Remove a devres group
629 * @dev: Device to remove group for
630 * @id: ID of target group, can be NULL
631 *
632 * Remove the group identified by @id. If @id is NULL, the latest
633 * open group is selected. Note that removing a group doesn't affect
634 * any other resources.
635 */
636void devres_remove_group(struct device *dev, void *id)
637{
638 struct devres_group *grp;
639 unsigned long flags;
640
641 spin_lock_irqsave(&dev->devres_lock, flags);
642
643 grp = find_group(dev, id);
644 if (grp) {
645 list_del_init(&grp->node[0].entry);
646 list_del_init(&grp->node[1].entry);
647 devres_log(dev, &grp->node[0], "REM");
648 } else
649 WARN_ON(1);
650
651 spin_unlock_irqrestore(&dev->devres_lock, flags);
652
653 kfree(grp);
654}
655EXPORT_SYMBOL_GPL(devres_remove_group);
656
657/**
658 * devres_release_group - Release resources in a devres group
659 * @dev: Device to release group for
660 * @id: ID of target group, can be NULL
661 *
662 * Release all resources in the group identified by @id. If @id is
663 * NULL, the latest open group is selected. The selected group and
664 * groups properly nested inside the selected group are removed.
665 *
666 * RETURNS:
667 * The number of released non-group resources.
668 */
669int devres_release_group(struct device *dev, void *id)
670{
671 struct devres_group *grp;
672 unsigned long flags;
673 LIST_HEAD(todo);
674 int cnt = 0;
675
676 spin_lock_irqsave(&dev->devres_lock, flags);
677
678 grp = find_group(dev, id);
679 if (grp) {
680 struct list_head *first = &grp->node[0].entry;
681 struct list_head *end = &dev->devres_head;
682
683 if (!list_empty(&grp->node[1].entry))
684 end = grp->node[1].entry.next;
685
686 cnt = remove_nodes(dev, first, end, &todo);
687 spin_unlock_irqrestore(&dev->devres_lock, flags);
688
689 release_nodes(dev, &todo);
690 } else {
691 WARN_ON(1);
692 spin_unlock_irqrestore(&dev->devres_lock, flags);
693 }
694
695 return cnt;
696}
697EXPORT_SYMBOL_GPL(devres_release_group);
698
699/*
700 * Custom devres actions allow inserting a simple function call
701 * into the teardown sequence.
702 */
703
704struct action_devres {
705 void *data;
706 void (*action)(void *);
707};
708
709static int devm_action_match(struct device *dev, void *res, void *p)
710{
711 struct action_devres *devres = res;
712 struct action_devres *target = p;
713
714 return devres->action == target->action &&
715 devres->data == target->data;
716}
717
718static void devm_action_release(struct device *dev, void *res)
719{
720 struct action_devres *devres = res;
721
722 devres->action(devres->data);
723}
724
725/**
726 * __devm_add_action() - add a custom action to list of managed resources
727 * @dev: Device that owns the action
728 * @action: Function that should be called
729 * @data: Pointer to data passed to @action implementation
730 * @name: Name of the resource (for debugging purposes)
731 *
732 * This adds a custom action to the list of managed resources so that
733 * it gets executed as part of standard resource unwinding.
734 */
735int __devm_add_action(struct device *dev, void (*action)(void *), void *data, const char *name)
736{
737 struct action_devres *devres;
738
739 devres = __devres_alloc_node(devm_action_release, sizeof(struct action_devres),
740 GFP_KERNEL, NUMA_NO_NODE, name);
741 if (!devres)
742 return -ENOMEM;
743
744 devres->data = data;
745 devres->action = action;
746
747 devres_add(dev, devres);
748 return 0;
749}
750EXPORT_SYMBOL_GPL(__devm_add_action);
751
752/**
753 * devm_remove_action() - removes previously added custom action
754 * @dev: Device that owns the action
755 * @action: Function implementing the action
756 * @data: Pointer to data passed to @action implementation
757 *
758 * Removes instance of @action previously added by devm_add_action().
759 * Both action and data should match one of the existing entries.
760 */
761void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
762{
763 struct action_devres devres = {
764 .data = data,
765 .action = action,
766 };
767
768 WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
769 &devres));
770}
771EXPORT_SYMBOL_GPL(devm_remove_action);
772
773/**
774 * devm_release_action() - release previously added custom action
775 * @dev: Device that owns the action
776 * @action: Function implementing the action
777 * @data: Pointer to data passed to @action implementation
778 *
779 * Releases and removes instance of @action previously added by
780 * devm_add_action(). Both action and data should match one of the
781 * existing entries.
782 */
783void devm_release_action(struct device *dev, void (*action)(void *), void *data)
784{
785 struct action_devres devres = {
786 .data = data,
787 .action = action,
788 };
789
790 WARN_ON(devres_release(dev, devm_action_release, devm_action_match,
791 &devres));
792
793}
794EXPORT_SYMBOL_GPL(devm_release_action);
795
796/*
797 * Managed kmalloc/kfree
798 */
799static void devm_kmalloc_release(struct device *dev, void *res)
800{
801 /* noop */
802}
803
804static int devm_kmalloc_match(struct device *dev, void *res, void *data)
805{
806 return res == data;
807}
808
809/**
810 * devm_kmalloc - Resource-managed kmalloc
811 * @dev: Device to allocate memory for
812 * @size: Allocation size
813 * @gfp: Allocation gfp flags
814 *
815 * Managed kmalloc. Memory allocated with this function is
816 * automatically freed on driver detach. Like all other devres
817 * resources, guaranteed alignment is unsigned long long.
818 *
819 * RETURNS:
820 * Pointer to allocated memory on success, NULL on failure.
821 */
822void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
823{
824 struct devres *dr;
825
826 if (unlikely(!size))
827 return ZERO_SIZE_PTR;
828
829 /* use raw alloc_dr for kmalloc caller tracing */
830 dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
831 if (unlikely(!dr))
832 return NULL;
833
834 /*
835 * This is named devm_kzalloc_release for historical reasons
836 * The initial implementation did not support kmalloc, only kzalloc
837 */
838 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
839 devres_add(dev, dr->data);
840 return dr->data;
841}
842EXPORT_SYMBOL_GPL(devm_kmalloc);
843
844/**
845 * devm_krealloc - Resource-managed krealloc()
846 * @dev: Device to re-allocate memory for
847 * @ptr: Pointer to the memory chunk to re-allocate
848 * @new_size: New allocation size
849 * @gfp: Allocation gfp flags
850 *
851 * Managed krealloc(). Resizes the memory chunk allocated with devm_kmalloc().
852 * Behaves similarly to regular krealloc(): if @ptr is NULL or ZERO_SIZE_PTR,
853 * it's the equivalent of devm_kmalloc(). If new_size is zero, it frees the
854 * previously allocated memory and returns ZERO_SIZE_PTR. This function doesn't
855 * change the order in which the release callback for the re-alloc'ed devres
856 * will be called (except when falling back to devm_kmalloc() or when freeing
857 * resources when new_size is zero). The contents of the memory are preserved
858 * up to the lesser of new and old sizes.
859 */
860void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
861{
862 size_t total_new_size, total_old_size;
863 struct devres *old_dr, *new_dr;
864 unsigned long flags;
865
866 if (unlikely(!new_size)) {
867 devm_kfree(dev, ptr);
868 return ZERO_SIZE_PTR;
869 }
870
871 if (unlikely(ZERO_OR_NULL_PTR(ptr)))
872 return devm_kmalloc(dev, new_size, gfp);
873
874 if (WARN_ON(is_kernel_rodata((unsigned long)ptr)))
875 /*
876 * We cannot reliably realloc a const string returned by
877 * devm_kstrdup_const().
878 */
879 return NULL;
880
881 if (!check_dr_size(new_size, &total_new_size))
882 return NULL;
883
884 total_old_size = ksize(container_of(ptr, struct devres, data));
885 if (total_old_size == 0) {
886 WARN(1, "Pointer doesn't point to dynamically allocated memory.");
887 return NULL;
888 }
889
890 /*
891 * If new size is smaller or equal to the actual number of bytes
892 * allocated previously - just return the same pointer.
893 */
894 if (total_new_size <= total_old_size)
895 return ptr;
896
897 /*
898 * Otherwise: allocate new, larger chunk. We need to allocate before
899 * taking the lock as most probably the caller uses GFP_KERNEL.
900 * alloc_dr() will call check_dr_size() to reserve extra memory
901 * for struct devres automatically, so size @new_size user request
902 * is delivered to it directly as devm_kmalloc() does.
903 */
904 new_dr = alloc_dr(devm_kmalloc_release,
905 new_size, gfp, dev_to_node(dev));
906 if (!new_dr)
907 return NULL;
908
909 /*
910 * The spinlock protects the linked list against concurrent
911 * modifications but not the resource itself.
912 */
913 spin_lock_irqsave(&dev->devres_lock, flags);
914
915 old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
916 if (!old_dr) {
917 spin_unlock_irqrestore(&dev->devres_lock, flags);
918 kfree(new_dr);
919 WARN(1, "Memory chunk not managed or managed by a different device.");
920 return NULL;
921 }
922
923 replace_dr(dev, &old_dr->node, &new_dr->node);
924
925 spin_unlock_irqrestore(&dev->devres_lock, flags);
926
927 /*
928 * We can copy the memory contents after releasing the lock as we're
929 * no longer modifying the list links.
930 */
931 memcpy(new_dr->data, old_dr->data,
932 total_old_size - offsetof(struct devres, data));
933 /*
934 * Same for releasing the old devres - it's now been removed from the
935 * list. This is also the reason why we must not use devm_kfree() - the
936 * links are no longer valid.
937 */
938 kfree(old_dr);
939
940 return new_dr->data;
941}
942EXPORT_SYMBOL_GPL(devm_krealloc);
943
944/**
945 * devm_kstrdup - Allocate resource managed space and
946 * copy an existing string into that.
947 * @dev: Device to allocate memory for
948 * @s: the string to duplicate
949 * @gfp: the GFP mask used in the devm_kmalloc() call when
950 * allocating memory
951 * RETURNS:
952 * Pointer to allocated string on success, NULL on failure.
953 */
954char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
955{
956 size_t size;
957 char *buf;
958
959 if (!s)
960 return NULL;
961
962 size = strlen(s) + 1;
963 buf = devm_kmalloc(dev, size, gfp);
964 if (buf)
965 memcpy(buf, s, size);
966 return buf;
967}
968EXPORT_SYMBOL_GPL(devm_kstrdup);
969
970/**
971 * devm_kstrdup_const - resource managed conditional string duplication
972 * @dev: device for which to duplicate the string
973 * @s: the string to duplicate
974 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
975 *
976 * Strings allocated by devm_kstrdup_const will be automatically freed when
977 * the associated device is detached.
978 *
979 * RETURNS:
980 * Source string if it is in .rodata section otherwise it falls back to
981 * devm_kstrdup.
982 */
983const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
984{
985 if (is_kernel_rodata((unsigned long)s))
986 return s;
987
988 return devm_kstrdup(dev, s, gfp);
989}
990EXPORT_SYMBOL_GPL(devm_kstrdup_const);
991
992/**
993 * devm_kvasprintf - Allocate resource managed space and format a string
994 * into that.
995 * @dev: Device to allocate memory for
996 * @gfp: the GFP mask used in the devm_kmalloc() call when
997 * allocating memory
998 * @fmt: The printf()-style format string
999 * @ap: Arguments for the format string
1000 * RETURNS:
1001 * Pointer to allocated string on success, NULL on failure.
1002 */
1003char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
1004 va_list ap)
1005{
1006 unsigned int len;
1007 char *p;
1008 va_list aq;
1009
1010 va_copy(aq, ap);
1011 len = vsnprintf(NULL, 0, fmt, aq);
1012 va_end(aq);
1013
1014 p = devm_kmalloc(dev, len+1, gfp);
1015 if (!p)
1016 return NULL;
1017
1018 vsnprintf(p, len+1, fmt, ap);
1019
1020 return p;
1021}
1022EXPORT_SYMBOL(devm_kvasprintf);
1023
1024/**
1025 * devm_kasprintf - Allocate resource managed space and format a string
1026 * into that.
1027 * @dev: Device to allocate memory for
1028 * @gfp: the GFP mask used in the devm_kmalloc() call when
1029 * allocating memory
1030 * @fmt: The printf()-style format string
1031 * @...: Arguments for the format string
1032 * RETURNS:
1033 * Pointer to allocated string on success, NULL on failure.
1034 */
1035char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
1036{
1037 va_list ap;
1038 char *p;
1039
1040 va_start(ap, fmt);
1041 p = devm_kvasprintf(dev, gfp, fmt, ap);
1042 va_end(ap);
1043
1044 return p;
1045}
1046EXPORT_SYMBOL_GPL(devm_kasprintf);
1047
1048/**
1049 * devm_kfree - Resource-managed kfree
1050 * @dev: Device this memory belongs to
1051 * @p: Memory to free
1052 *
1053 * Free memory allocated with devm_kmalloc().
1054 */
1055void devm_kfree(struct device *dev, const void *p)
1056{
1057 int rc;
1058
1059 /*
1060 * Special cases: pointer to a string in .rodata returned by
1061 * devm_kstrdup_const() or NULL/ZERO ptr.
1062 */
1063 if (unlikely(is_kernel_rodata((unsigned long)p) || ZERO_OR_NULL_PTR(p)))
1064 return;
1065
1066 rc = devres_destroy(dev, devm_kmalloc_release,
1067 devm_kmalloc_match, (void *)p);
1068 WARN_ON(rc);
1069}
1070EXPORT_SYMBOL_GPL(devm_kfree);
1071
1072/**
1073 * devm_kmemdup - Resource-managed kmemdup
1074 * @dev: Device this memory belongs to
1075 * @src: Memory region to duplicate
1076 * @len: Memory region length
1077 * @gfp: GFP mask to use
1078 *
1079 * Duplicate region of a memory using resource managed kmalloc
1080 */
1081void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
1082{
1083 void *p;
1084
1085 p = devm_kmalloc(dev, len, gfp);
1086 if (p)
1087 memcpy(p, src, len);
1088
1089 return p;
1090}
1091EXPORT_SYMBOL_GPL(devm_kmemdup);
1092
1093struct pages_devres {
1094 unsigned long addr;
1095 unsigned int order;
1096};
1097
1098static int devm_pages_match(struct device *dev, void *res, void *p)
1099{
1100 struct pages_devres *devres = res;
1101 struct pages_devres *target = p;
1102
1103 return devres->addr == target->addr;
1104}
1105
1106static void devm_pages_release(struct device *dev, void *res)
1107{
1108 struct pages_devres *devres = res;
1109
1110 free_pages(devres->addr, devres->order);
1111}
1112
1113/**
1114 * devm_get_free_pages - Resource-managed __get_free_pages
1115 * @dev: Device to allocate memory for
1116 * @gfp_mask: Allocation gfp flags
1117 * @order: Allocation size is (1 << order) pages
1118 *
1119 * Managed get_free_pages. Memory allocated with this function is
1120 * automatically freed on driver detach.
1121 *
1122 * RETURNS:
1123 * Address of allocated memory on success, 0 on failure.
1124 */
1125
1126unsigned long devm_get_free_pages(struct device *dev,
1127 gfp_t gfp_mask, unsigned int order)
1128{
1129 struct pages_devres *devres;
1130 unsigned long addr;
1131
1132 addr = __get_free_pages(gfp_mask, order);
1133
1134 if (unlikely(!addr))
1135 return 0;
1136
1137 devres = devres_alloc(devm_pages_release,
1138 sizeof(struct pages_devres), GFP_KERNEL);
1139 if (unlikely(!devres)) {
1140 free_pages(addr, order);
1141 return 0;
1142 }
1143
1144 devres->addr = addr;
1145 devres->order = order;
1146
1147 devres_add(dev, devres);
1148 return addr;
1149}
1150EXPORT_SYMBOL_GPL(devm_get_free_pages);
1151
1152/**
1153 * devm_free_pages - Resource-managed free_pages
1154 * @dev: Device this memory belongs to
1155 * @addr: Memory to free
1156 *
1157 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
1158 * there is no need to supply the @order.
1159 */
1160void devm_free_pages(struct device *dev, unsigned long addr)
1161{
1162 struct pages_devres devres = { .addr = addr };
1163
1164 WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
1165 &devres));
1166}
1167EXPORT_SYMBOL_GPL(devm_free_pages);
1168
1169static void devm_percpu_release(struct device *dev, void *pdata)
1170{
1171 void __percpu *p;
1172
1173 p = *(void __percpu **)pdata;
1174 free_percpu(p);
1175}
1176
1177static int devm_percpu_match(struct device *dev, void *data, void *p)
1178{
1179 struct devres *devr = container_of(data, struct devres, data);
1180
1181 return *(void **)devr->data == p;
1182}
1183
1184/**
1185 * __devm_alloc_percpu - Resource-managed alloc_percpu
1186 * @dev: Device to allocate per-cpu memory for
1187 * @size: Size of per-cpu memory to allocate
1188 * @align: Alignment of per-cpu memory to allocate
1189 *
1190 * Managed alloc_percpu. Per-cpu memory allocated with this function is
1191 * automatically freed on driver detach.
1192 *
1193 * RETURNS:
1194 * Pointer to allocated memory on success, NULL on failure.
1195 */
1196void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1197 size_t align)
1198{
1199 void *p;
1200 void __percpu *pcpu;
1201
1202 pcpu = __alloc_percpu(size, align);
1203 if (!pcpu)
1204 return NULL;
1205
1206 p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1207 if (!p) {
1208 free_percpu(pcpu);
1209 return NULL;
1210 }
1211
1212 *(void __percpu **)p = pcpu;
1213
1214 devres_add(dev, p);
1215
1216 return pcpu;
1217}
1218EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1219
1220/**
1221 * devm_free_percpu - Resource-managed free_percpu
1222 * @dev: Device this memory belongs to
1223 * @pdata: Per-cpu memory to free
1224 *
1225 * Free memory allocated with devm_alloc_percpu().
1226 */
1227void devm_free_percpu(struct device *dev, void __percpu *pdata)
1228{
1229 /*
1230 * Use devres_release() to prevent memory leakage as
1231 * devm_free_pages() does.
1232 */
1233 WARN_ON(devres_release(dev, devm_percpu_release, devm_percpu_match,
1234 (void *)(__force unsigned long)pdata));
1235}
1236EXPORT_SYMBOL_GPL(devm_free_percpu);