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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/*
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);