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