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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#include "trace.h"
18
19struct devres_node {
20 struct list_head entry;
21 dr_release_t release;
22 const char *name;
23 size_t size;
24};
25
26struct devres {
27 struct devres_node node;
28 /*
29 * Some archs want to perform DMA into kmalloc caches
30 * and need a guaranteed alignment larger than
31 * the alignment of a 64-bit integer.
32 * Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same
33 * buffer alignment as if it was allocated by plain kmalloc().
34 */
35 u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];
36};
37
38struct devres_group {
39 struct devres_node node[2];
40 void *id;
41 int color;
42 /* -- 8 pointers */
43};
44
45static void set_node_dbginfo(struct devres_node *node, const char *name,
46 size_t size)
47{
48 node->name = name;
49 node->size = size;
50}
51
52#ifdef CONFIG_DEBUG_DEVRES
53static int log_devres = 0;
54module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
55
56static void devres_dbg(struct device *dev, struct devres_node *node,
57 const char *op)
58{
59 if (unlikely(log_devres))
60 dev_err(dev, "DEVRES %3s %p %s (%zu bytes)\n",
61 op, node, node->name, node->size);
62}
63#else /* CONFIG_DEBUG_DEVRES */
64#define devres_dbg(dev, node, op) do {} while (0)
65#endif /* CONFIG_DEBUG_DEVRES */
66
67static void devres_log(struct device *dev, struct devres_node *node,
68 const char *op)
69{
70 trace_devres_log(dev, op, node, node->name, node->size);
71 devres_dbg(dev, node, op);
72}
73
74/*
75 * Release functions for devres group. These callbacks are used only
76 * for identification.
77 */
78static void group_open_release(struct device *dev, void *res)
79{
80 /* noop */
81}
82
83static void group_close_release(struct device *dev, void *res)
84{
85 /* noop */
86}
87
88static struct devres_group * node_to_group(struct devres_node *node)
89{
90 if (node->release == &group_open_release)
91 return container_of(node, struct devres_group, node[0]);
92 if (node->release == &group_close_release)
93 return container_of(node, struct devres_group, node[1]);
94 return NULL;
95}
96
97static bool check_dr_size(size_t size, size_t *tot_size)
98{
99 /* We must catch any near-SIZE_MAX cases that could overflow. */
100 if (unlikely(check_add_overflow(sizeof(struct devres),
101 size, tot_size)))
102 return false;
103
104 return true;
105}
106
107static __always_inline struct devres * alloc_dr(dr_release_t release,
108 size_t size, gfp_t gfp, int nid)
109{
110 size_t tot_size;
111 struct devres *dr;
112
113 if (!check_dr_size(size, &tot_size))
114 return NULL;
115
116 dr = kmalloc_node_track_caller(tot_size, gfp, nid);
117 if (unlikely(!dr))
118 return NULL;
119
120 memset(dr, 0, offsetof(struct devres, data));
121
122 INIT_LIST_HEAD(&dr->node.entry);
123 dr->node.release = release;
124 return dr;
125}
126
127static void add_dr(struct device *dev, struct devres_node *node)
128{
129 devres_log(dev, node, "ADD");
130 BUG_ON(!list_empty(&node->entry));
131 list_add_tail(&node->entry, &dev->devres_head);
132}
133
134static void replace_dr(struct device *dev,
135 struct devres_node *old, struct devres_node *new)
136{
137 devres_log(dev, old, "REPLACE");
138 BUG_ON(!list_empty(&new->entry));
139 list_replace(&old->entry, &new->entry);
140}
141
142/**
143 * __devres_alloc_node - Allocate device resource data
144 * @release: Release function devres will be associated with
145 * @size: Allocation size
146 * @gfp: Allocation flags
147 * @nid: NUMA node
148 * @name: Name of the resource
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 const char *name)
159{
160 struct devres *dr;
161
162 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
163 if (unlikely(!dr))
164 return NULL;
165 set_node_dbginfo(&dr->node, name, size);
166 return dr->data;
167}
168EXPORT_SYMBOL_GPL(__devres_alloc_node);
169
170/**
171 * devres_for_each_res - Resource iterator
172 * @dev: Device to iterate resource from
173 * @release: Look for resources associated with this release function
174 * @match: Match function (optional)
175 * @match_data: Data for the match function
176 * @fn: Function to be called for each matched resource.
177 * @data: Data for @fn, the 3rd parameter of @fn
178 *
179 * Call @fn for each devres of @dev which is associated with @release
180 * and for which @match returns 1.
181 *
182 * RETURNS:
183 * void
184 */
185void devres_for_each_res(struct device *dev, dr_release_t release,
186 dr_match_t match, void *match_data,
187 void (*fn)(struct device *, void *, void *),
188 void *data)
189{
190 struct devres_node *node;
191 struct devres_node *tmp;
192 unsigned long flags;
193
194 if (!fn)
195 return;
196
197 spin_lock_irqsave(&dev->devres_lock, flags);
198 list_for_each_entry_safe_reverse(node, tmp,
199 &dev->devres_head, entry) {
200 struct devres *dr = container_of(node, struct devres, node);
201
202 if (node->release != release)
203 continue;
204 if (match && !match(dev, dr->data, match_data))
205 continue;
206 fn(dev, dr->data, data);
207 }
208 spin_unlock_irqrestore(&dev->devres_lock, flags);
209}
210EXPORT_SYMBOL_GPL(devres_for_each_res);
211
212/**
213 * devres_free - Free device resource data
214 * @res: Pointer to devres data to free
215 *
216 * Free devres created with devres_alloc().
217 */
218void devres_free(void *res)
219{
220 if (res) {
221 struct devres *dr = container_of(res, struct devres, data);
222
223 BUG_ON(!list_empty(&dr->node.entry));
224 kfree(dr);
225 }
226}
227EXPORT_SYMBOL_GPL(devres_free);
228
229/**
230 * devres_add - Register device resource
231 * @dev: Device to add resource to
232 * @res: Resource to register
233 *
234 * Register devres @res to @dev. @res should have been allocated
235 * using devres_alloc(). On driver detach, the associated release
236 * function will be invoked and devres will be freed automatically.
237 */
238void devres_add(struct device *dev, void *res)
239{
240 struct devres *dr = container_of(res, struct devres, data);
241 unsigned long flags;
242
243 spin_lock_irqsave(&dev->devres_lock, flags);
244 add_dr(dev, &dr->node);
245 spin_unlock_irqrestore(&dev->devres_lock, flags);
246}
247EXPORT_SYMBOL_GPL(devres_add);
248
249static struct devres *find_dr(struct device *dev, dr_release_t release,
250 dr_match_t match, void *match_data)
251{
252 struct devres_node *node;
253
254 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
255 struct devres *dr = container_of(node, struct devres, node);
256
257 if (node->release != release)
258 continue;
259 if (match && !match(dev, dr->data, match_data))
260 continue;
261 return dr;
262 }
263
264 return NULL;
265}
266
267/**
268 * devres_find - Find device resource
269 * @dev: Device to lookup resource from
270 * @release: Look for resources associated with this release function
271 * @match: Match function (optional)
272 * @match_data: Data for the match function
273 *
274 * Find the latest devres of @dev which is associated with @release
275 * and for which @match returns 1. If @match is NULL, it's considered
276 * to match all.
277 *
278 * RETURNS:
279 * Pointer to found devres, NULL if not found.
280 */
281void * devres_find(struct device *dev, dr_release_t release,
282 dr_match_t match, void *match_data)
283{
284 struct devres *dr;
285 unsigned long flags;
286
287 spin_lock_irqsave(&dev->devres_lock, flags);
288 dr = find_dr(dev, release, match, match_data);
289 spin_unlock_irqrestore(&dev->devres_lock, flags);
290
291 if (dr)
292 return dr->data;
293 return NULL;
294}
295EXPORT_SYMBOL_GPL(devres_find);
296
297/**
298 * devres_get - Find devres, if non-existent, add one atomically
299 * @dev: Device to lookup or add devres for
300 * @new_res: Pointer to new initialized devres to add if not found
301 * @match: Match function (optional)
302 * @match_data: Data for the match function
303 *
304 * Find the latest devres of @dev which has the same release function
305 * as @new_res and for which @match return 1. If found, @new_res is
306 * freed; otherwise, @new_res is added atomically.
307 *
308 * RETURNS:
309 * Pointer to found or added devres.
310 */
311void * devres_get(struct device *dev, void *new_res,
312 dr_match_t match, void *match_data)
313{
314 struct devres *new_dr = container_of(new_res, struct devres, data);
315 struct devres *dr;
316 unsigned long flags;
317
318 spin_lock_irqsave(&dev->devres_lock, flags);
319 dr = find_dr(dev, new_dr->node.release, match, match_data);
320 if (!dr) {
321 add_dr(dev, &new_dr->node);
322 dr = new_dr;
323 new_res = NULL;
324 }
325 spin_unlock_irqrestore(&dev->devres_lock, flags);
326 devres_free(new_res);
327
328 return dr->data;
329}
330EXPORT_SYMBOL_GPL(devres_get);
331
332/**
333 * devres_remove - Find a device resource and remove it
334 * @dev: Device to find resource from
335 * @release: Look for resources associated with this release function
336 * @match: Match function (optional)
337 * @match_data: Data for the match function
338 *
339 * Find the latest devres of @dev associated with @release and for
340 * which @match returns 1. If @match is NULL, it's considered to
341 * match all. If found, the resource is removed atomically and
342 * returned.
343 *
344 * RETURNS:
345 * Pointer to removed devres on success, NULL if not found.
346 */
347void * devres_remove(struct device *dev, dr_release_t release,
348 dr_match_t match, void *match_data)
349{
350 struct devres *dr;
351 unsigned long flags;
352
353 spin_lock_irqsave(&dev->devres_lock, flags);
354 dr = find_dr(dev, release, match, match_data);
355 if (dr) {
356 list_del_init(&dr->node.entry);
357 devres_log(dev, &dr->node, "REM");
358 }
359 spin_unlock_irqrestore(&dev->devres_lock, flags);
360
361 if (dr)
362 return dr->data;
363 return NULL;
364}
365EXPORT_SYMBOL_GPL(devres_remove);
366
367/**
368 * devres_destroy - Find a device resource and destroy it
369 * @dev: Device to find resource from
370 * @release: Look for resources associated with this release function
371 * @match: Match function (optional)
372 * @match_data: Data for the match function
373 *
374 * Find the latest devres of @dev associated with @release and for
375 * which @match returns 1. If @match is NULL, it's considered to
376 * match all. If found, the resource is removed atomically and freed.
377 *
378 * Note that the release function for the resource will not be called,
379 * only the devres-allocated data will be freed. The caller becomes
380 * responsible for freeing any other data.
381 *
382 * RETURNS:
383 * 0 if devres is found and freed, -ENOENT if not found.
384 */
385int devres_destroy(struct device *dev, dr_release_t release,
386 dr_match_t match, void *match_data)
387{
388 void *res;
389
390 res = devres_remove(dev, release, match, match_data);
391 if (unlikely(!res))
392 return -ENOENT;
393
394 devres_free(res);
395 return 0;
396}
397EXPORT_SYMBOL_GPL(devres_destroy);
398
399
400/**
401 * devres_release - Find a device resource and destroy it, calling release
402 * @dev: Device to find resource from
403 * @release: Look for resources associated with this release function
404 * @match: Match function (optional)
405 * @match_data: Data for the match function
406 *
407 * Find the latest devres of @dev associated with @release and for
408 * which @match returns 1. If @match is NULL, it's considered to
409 * match all. If found, the resource is removed atomically, the
410 * release function called and the resource freed.
411 *
412 * RETURNS:
413 * 0 if devres is found and freed, -ENOENT if not found.
414 */
415int devres_release(struct device *dev, dr_release_t release,
416 dr_match_t match, void *match_data)
417{
418 void *res;
419
420 res = devres_remove(dev, release, match, match_data);
421 if (unlikely(!res))
422 return -ENOENT;
423
424 (*release)(dev, res);
425 devres_free(res);
426 return 0;
427}
428EXPORT_SYMBOL_GPL(devres_release);
429
430static int remove_nodes(struct device *dev,
431 struct list_head *first, struct list_head *end,
432 struct list_head *todo)
433{
434 struct devres_node *node, *n;
435 int cnt = 0, nr_groups = 0;
436
437 /* First pass - move normal devres entries to @todo and clear
438 * devres_group colors.
439 */
440 node = list_entry(first, struct devres_node, entry);
441 list_for_each_entry_safe_from(node, n, end, entry) {
442 struct devres_group *grp;
443
444 grp = node_to_group(node);
445 if (grp) {
446 /* clear color of group markers in the first pass */
447 grp->color = 0;
448 nr_groups++;
449 } else {
450 /* regular devres entry */
451 if (&node->entry == first)
452 first = first->next;
453 list_move_tail(&node->entry, todo);
454 cnt++;
455 }
456 }
457
458 if (!nr_groups)
459 return cnt;
460
461 /* Second pass - Scan groups and color them. A group gets
462 * color value of two iff the group is wholly contained in
463 * [current node, end). That is, for a closed group, both opening
464 * and closing markers should be in the range, while just the
465 * opening marker is enough for an open group.
466 */
467 node = list_entry(first, struct devres_node, entry);
468 list_for_each_entry_safe_from(node, n, end, entry) {
469 struct devres_group *grp;
470
471 grp = node_to_group(node);
472 BUG_ON(!grp || list_empty(&grp->node[0].entry));
473
474 grp->color++;
475 if (list_empty(&grp->node[1].entry))
476 grp->color++;
477
478 BUG_ON(grp->color <= 0 || grp->color > 2);
479 if (grp->color == 2) {
480 /* No need to update current node or end. The removed
481 * nodes are always before both.
482 */
483 list_move_tail(&grp->node[0].entry, todo);
484 list_del_init(&grp->node[1].entry);
485 }
486 }
487
488 return cnt;
489}
490
491static void release_nodes(struct device *dev, struct list_head *todo)
492{
493 struct devres *dr, *tmp;
494
495 /* Release. Note that both devres and devres_group are
496 * handled as devres in the following loop. This is safe.
497 */
498 list_for_each_entry_safe_reverse(dr, tmp, todo, node.entry) {
499 devres_log(dev, &dr->node, "REL");
500 dr->node.release(dev, dr->data);
501 kfree(dr);
502 }
503}
504
505/**
506 * devres_release_all - Release all managed resources
507 * @dev: Device to release resources for
508 *
509 * Release all resources associated with @dev. This function is
510 * called on driver detach.
511 */
512int devres_release_all(struct device *dev)
513{
514 unsigned long flags;
515 LIST_HEAD(todo);
516 int cnt;
517
518 /* Looks like an uninitialized device structure */
519 if (WARN_ON(dev->devres_head.next == NULL))
520 return -ENODEV;
521
522 /* Nothing to release if list is empty */
523 if (list_empty(&dev->devres_head))
524 return 0;
525
526 spin_lock_irqsave(&dev->devres_lock, flags);
527 cnt = remove_nodes(dev, dev->devres_head.next, &dev->devres_head, &todo);
528 spin_unlock_irqrestore(&dev->devres_lock, flags);
529
530 release_nodes(dev, &todo);
531 return cnt;
532}
533
534/**
535 * devres_open_group - Open a new devres group
536 * @dev: Device to open devres group for
537 * @id: Separator ID
538 * @gfp: Allocation flags
539 *
540 * Open a new devres group for @dev with @id. For @id, using a
541 * pointer to an object which won't be used for another group is
542 * recommended. If @id is NULL, address-wise unique ID is created.
543 *
544 * RETURNS:
545 * ID of the new group, NULL on failure.
546 */
547void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
548{
549 struct devres_group *grp;
550 unsigned long flags;
551
552 grp = kmalloc(sizeof(*grp), gfp);
553 if (unlikely(!grp))
554 return NULL;
555
556 grp->node[0].release = &group_open_release;
557 grp->node[1].release = &group_close_release;
558 INIT_LIST_HEAD(&grp->node[0].entry);
559 INIT_LIST_HEAD(&grp->node[1].entry);
560 set_node_dbginfo(&grp->node[0], "grp<", 0);
561 set_node_dbginfo(&grp->node[1], "grp>", 0);
562 grp->id = grp;
563 if (id)
564 grp->id = id;
565
566 spin_lock_irqsave(&dev->devres_lock, flags);
567 add_dr(dev, &grp->node[0]);
568 spin_unlock_irqrestore(&dev->devres_lock, flags);
569 return grp->id;
570}
571EXPORT_SYMBOL_GPL(devres_open_group);
572
573/* Find devres group with ID @id. If @id is NULL, look for the latest. */
574static struct devres_group * find_group(struct device *dev, void *id)
575{
576 struct devres_node *node;
577
578 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
579 struct devres_group *grp;
580
581 if (node->release != &group_open_release)
582 continue;
583
584 grp = container_of(node, struct devres_group, node[0]);
585
586 if (id) {
587 if (grp->id == id)
588 return grp;
589 } else if (list_empty(&grp->node[1].entry))
590 return grp;
591 }
592
593 return NULL;
594}
595
596/**
597 * devres_close_group - Close a devres group
598 * @dev: Device to close devres group for
599 * @id: ID of target group, can be NULL
600 *
601 * Close the group identified by @id. If @id is NULL, the latest open
602 * group is selected.
603 */
604void devres_close_group(struct device *dev, void *id)
605{
606 struct devres_group *grp;
607 unsigned long flags;
608
609 spin_lock_irqsave(&dev->devres_lock, flags);
610
611 grp = find_group(dev, id);
612 if (grp)
613 add_dr(dev, &grp->node[1]);
614 else
615 WARN_ON(1);
616
617 spin_unlock_irqrestore(&dev->devres_lock, flags);
618}
619EXPORT_SYMBOL_GPL(devres_close_group);
620
621/**
622 * devres_remove_group - Remove a devres group
623 * @dev: Device to remove group for
624 * @id: ID of target group, can be NULL
625 *
626 * Remove the group identified by @id. If @id is NULL, the latest
627 * open group is selected. Note that removing a group doesn't affect
628 * any other resources.
629 */
630void devres_remove_group(struct device *dev, void *id)
631{
632 struct devres_group *grp;
633 unsigned long flags;
634
635 spin_lock_irqsave(&dev->devres_lock, flags);
636
637 grp = find_group(dev, id);
638 if (grp) {
639 list_del_init(&grp->node[0].entry);
640 list_del_init(&grp->node[1].entry);
641 devres_log(dev, &grp->node[0], "REM");
642 } else
643 WARN_ON(1);
644
645 spin_unlock_irqrestore(&dev->devres_lock, flags);
646
647 kfree(grp);
648}
649EXPORT_SYMBOL_GPL(devres_remove_group);
650
651/**
652 * devres_release_group - Release resources in a devres group
653 * @dev: Device to release group for
654 * @id: ID of target group, can be NULL
655 *
656 * Release all resources in the group identified by @id. If @id is
657 * NULL, the latest open group is selected. The selected group and
658 * groups properly nested inside the selected group are removed.
659 *
660 * RETURNS:
661 * The number of released non-group resources.
662 */
663int devres_release_group(struct device *dev, void *id)
664{
665 struct devres_group *grp;
666 unsigned long flags;
667 LIST_HEAD(todo);
668 int cnt = 0;
669
670 spin_lock_irqsave(&dev->devres_lock, flags);
671
672 grp = find_group(dev, id);
673 if (grp) {
674 struct list_head *first = &grp->node[0].entry;
675 struct list_head *end = &dev->devres_head;
676
677 if (!list_empty(&grp->node[1].entry))
678 end = grp->node[1].entry.next;
679
680 cnt = remove_nodes(dev, first, end, &todo);
681 spin_unlock_irqrestore(&dev->devres_lock, flags);
682
683 release_nodes(dev, &todo);
684 } else {
685 WARN_ON(1);
686 spin_unlock_irqrestore(&dev->devres_lock, flags);
687 }
688
689 return cnt;
690}
691EXPORT_SYMBOL_GPL(devres_release_group);
692
693/*
694 * Custom devres actions allow inserting a simple function call
695 * into the teadown sequence.
696 */
697
698struct action_devres {
699 void *data;
700 void (*action)(void *);
701};
702
703static int devm_action_match(struct device *dev, void *res, void *p)
704{
705 struct action_devres *devres = res;
706 struct action_devres *target = p;
707
708 return devres->action == target->action &&
709 devres->data == target->data;
710}
711
712static void devm_action_release(struct device *dev, void *res)
713{
714 struct action_devres *devres = res;
715
716 devres->action(devres->data);
717}
718
719/**
720 * devm_add_action() - add a custom action to list of managed resources
721 * @dev: Device that owns the action
722 * @action: Function that should be called
723 * @data: Pointer to data passed to @action implementation
724 *
725 * This adds a custom action to the list of managed resources so that
726 * it gets executed as part of standard resource unwinding.
727 */
728int devm_add_action(struct device *dev, void (*action)(void *), void *data)
729{
730 struct action_devres *devres;
731
732 devres = devres_alloc(devm_action_release,
733 sizeof(struct action_devres), GFP_KERNEL);
734 if (!devres)
735 return -ENOMEM;
736
737 devres->data = data;
738 devres->action = action;
739
740 devres_add(dev, devres);
741 return 0;
742}
743EXPORT_SYMBOL_GPL(devm_add_action);
744
745/**
746 * devm_remove_action() - removes previously added custom action
747 * @dev: Device that owns the action
748 * @action: Function implementing the action
749 * @data: Pointer to data passed to @action implementation
750 *
751 * Removes instance of @action previously added by devm_add_action().
752 * Both action and data should match one of the existing entries.
753 */
754void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
755{
756 struct action_devres devres = {
757 .data = data,
758 .action = action,
759 };
760
761 WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
762 &devres));
763}
764EXPORT_SYMBOL_GPL(devm_remove_action);
765
766/**
767 * devm_release_action() - release previously added custom action
768 * @dev: Device that owns the action
769 * @action: Function implementing the action
770 * @data: Pointer to data passed to @action implementation
771 *
772 * Releases and removes instance of @action previously added by
773 * devm_add_action(). Both action and data should match one of the
774 * existing entries.
775 */
776void devm_release_action(struct device *dev, void (*action)(void *), void *data)
777{
778 struct action_devres devres = {
779 .data = data,
780 .action = action,
781 };
782
783 WARN_ON(devres_release(dev, devm_action_release, devm_action_match,
784 &devres));
785
786}
787EXPORT_SYMBOL_GPL(devm_release_action);
788
789/*
790 * Managed kmalloc/kfree
791 */
792static void devm_kmalloc_release(struct device *dev, void *res)
793{
794 /* noop */
795}
796
797static int devm_kmalloc_match(struct device *dev, void *res, void *data)
798{
799 return res == data;
800}
801
802/**
803 * devm_kmalloc - Resource-managed kmalloc
804 * @dev: Device to allocate memory for
805 * @size: Allocation size
806 * @gfp: Allocation gfp flags
807 *
808 * Managed kmalloc. Memory allocated with this function is
809 * automatically freed on driver detach. Like all other devres
810 * resources, guaranteed alignment is unsigned long long.
811 *
812 * RETURNS:
813 * Pointer to allocated memory on success, NULL on failure.
814 */
815void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
816{
817 struct devres *dr;
818
819 if (unlikely(!size))
820 return ZERO_SIZE_PTR;
821
822 /* use raw alloc_dr for kmalloc caller tracing */
823 dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
824 if (unlikely(!dr))
825 return NULL;
826
827 /*
828 * This is named devm_kzalloc_release for historical reasons
829 * The initial implementation did not support kmalloc, only kzalloc
830 */
831 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
832 devres_add(dev, dr->data);
833 return dr->data;
834}
835EXPORT_SYMBOL_GPL(devm_kmalloc);
836
837/**
838 * devm_krealloc - Resource-managed krealloc()
839 * @dev: Device to re-allocate memory for
840 * @ptr: Pointer to the memory chunk to re-allocate
841 * @new_size: New allocation size
842 * @gfp: Allocation gfp flags
843 *
844 * Managed krealloc(). Resizes the memory chunk allocated with devm_kmalloc().
845 * Behaves similarly to regular krealloc(): if @ptr is NULL or ZERO_SIZE_PTR,
846 * it's the equivalent of devm_kmalloc(). If new_size is zero, it frees the
847 * previously allocated memory and returns ZERO_SIZE_PTR. This function doesn't
848 * change the order in which the release callback for the re-alloc'ed devres
849 * will be called (except when falling back to devm_kmalloc() or when freeing
850 * resources when new_size is zero). The contents of the memory are preserved
851 * up to the lesser of new and old sizes.
852 */
853void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
854{
855 size_t total_new_size, total_old_size;
856 struct devres *old_dr, *new_dr;
857 unsigned long flags;
858
859 if (unlikely(!new_size)) {
860 devm_kfree(dev, ptr);
861 return ZERO_SIZE_PTR;
862 }
863
864 if (unlikely(ZERO_OR_NULL_PTR(ptr)))
865 return devm_kmalloc(dev, new_size, gfp);
866
867 if (WARN_ON(is_kernel_rodata((unsigned long)ptr)))
868 /*
869 * We cannot reliably realloc a const string returned by
870 * devm_kstrdup_const().
871 */
872 return NULL;
873
874 if (!check_dr_size(new_size, &total_new_size))
875 return NULL;
876
877 total_old_size = ksize(container_of(ptr, struct devres, data));
878 if (total_old_size == 0) {
879 WARN(1, "Pointer doesn't point to dynamically allocated memory.");
880 return NULL;
881 }
882
883 /*
884 * If new size is smaller or equal to the actual number of bytes
885 * allocated previously - just return the same pointer.
886 */
887 if (total_new_size <= total_old_size)
888 return ptr;
889
890 /*
891 * Otherwise: allocate new, larger chunk. We need to allocate before
892 * taking the lock as most probably the caller uses GFP_KERNEL.
893 */
894 new_dr = alloc_dr(devm_kmalloc_release,
895 total_new_size, gfp, dev_to_node(dev));
896 if (!new_dr)
897 return NULL;
898
899 /*
900 * The spinlock protects the linked list against concurrent
901 * modifications but not the resource itself.
902 */
903 spin_lock_irqsave(&dev->devres_lock, flags);
904
905 old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
906 if (!old_dr) {
907 spin_unlock_irqrestore(&dev->devres_lock, flags);
908 kfree(new_dr);
909 WARN(1, "Memory chunk not managed or managed by a different device.");
910 return NULL;
911 }
912
913 replace_dr(dev, &old_dr->node, &new_dr->node);
914
915 spin_unlock_irqrestore(&dev->devres_lock, flags);
916
917 /*
918 * We can copy the memory contents after releasing the lock as we're
919 * no longer modyfing the list links.
920 */
921 memcpy(new_dr->data, old_dr->data,
922 total_old_size - offsetof(struct devres, data));
923 /*
924 * Same for releasing the old devres - it's now been removed from the
925 * list. This is also the reason why we must not use devm_kfree() - the
926 * links are no longer valid.
927 */
928 kfree(old_dr);
929
930 return new_dr->data;
931}
932EXPORT_SYMBOL_GPL(devm_krealloc);
933
934/**
935 * devm_kstrdup - Allocate resource managed space and
936 * copy an existing string into that.
937 * @dev: Device to allocate memory for
938 * @s: the string to duplicate
939 * @gfp: the GFP mask used in the devm_kmalloc() call when
940 * allocating memory
941 * RETURNS:
942 * Pointer to allocated string on success, NULL on failure.
943 */
944char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
945{
946 size_t size;
947 char *buf;
948
949 if (!s)
950 return NULL;
951
952 size = strlen(s) + 1;
953 buf = devm_kmalloc(dev, size, gfp);
954 if (buf)
955 memcpy(buf, s, size);
956 return buf;
957}
958EXPORT_SYMBOL_GPL(devm_kstrdup);
959
960/**
961 * devm_kstrdup_const - resource managed conditional string duplication
962 * @dev: device for which to duplicate the string
963 * @s: the string to duplicate
964 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
965 *
966 * Strings allocated by devm_kstrdup_const will be automatically freed when
967 * the associated device is detached.
968 *
969 * RETURNS:
970 * Source string if it is in .rodata section otherwise it falls back to
971 * devm_kstrdup.
972 */
973const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
974{
975 if (is_kernel_rodata((unsigned long)s))
976 return s;
977
978 return devm_kstrdup(dev, s, gfp);
979}
980EXPORT_SYMBOL_GPL(devm_kstrdup_const);
981
982/**
983 * devm_kvasprintf - Allocate resource managed space and format a string
984 * into that.
985 * @dev: Device to allocate memory for
986 * @gfp: the GFP mask used in the devm_kmalloc() call when
987 * allocating memory
988 * @fmt: The printf()-style format string
989 * @ap: Arguments for the format string
990 * RETURNS:
991 * Pointer to allocated string on success, NULL on failure.
992 */
993char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
994 va_list ap)
995{
996 unsigned int len;
997 char *p;
998 va_list aq;
999
1000 va_copy(aq, ap);
1001 len = vsnprintf(NULL, 0, fmt, aq);
1002 va_end(aq);
1003
1004 p = devm_kmalloc(dev, len+1, gfp);
1005 if (!p)
1006 return NULL;
1007
1008 vsnprintf(p, len+1, fmt, ap);
1009
1010 return p;
1011}
1012EXPORT_SYMBOL(devm_kvasprintf);
1013
1014/**
1015 * devm_kasprintf - Allocate resource managed space and format a string
1016 * into that.
1017 * @dev: Device to allocate memory for
1018 * @gfp: the GFP mask used in the devm_kmalloc() call when
1019 * allocating memory
1020 * @fmt: The printf()-style format string
1021 * @...: Arguments for the format string
1022 * RETURNS:
1023 * Pointer to allocated string on success, NULL on failure.
1024 */
1025char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
1026{
1027 va_list ap;
1028 char *p;
1029
1030 va_start(ap, fmt);
1031 p = devm_kvasprintf(dev, gfp, fmt, ap);
1032 va_end(ap);
1033
1034 return p;
1035}
1036EXPORT_SYMBOL_GPL(devm_kasprintf);
1037
1038/**
1039 * devm_kfree - Resource-managed kfree
1040 * @dev: Device this memory belongs to
1041 * @p: Memory to free
1042 *
1043 * Free memory allocated with devm_kmalloc().
1044 */
1045void devm_kfree(struct device *dev, const void *p)
1046{
1047 int rc;
1048
1049 /*
1050 * Special cases: pointer to a string in .rodata returned by
1051 * devm_kstrdup_const() or NULL/ZERO ptr.
1052 */
1053 if (unlikely(is_kernel_rodata((unsigned long)p) || ZERO_OR_NULL_PTR(p)))
1054 return;
1055
1056 rc = devres_destroy(dev, devm_kmalloc_release,
1057 devm_kmalloc_match, (void *)p);
1058 WARN_ON(rc);
1059}
1060EXPORT_SYMBOL_GPL(devm_kfree);
1061
1062/**
1063 * devm_kmemdup - Resource-managed kmemdup
1064 * @dev: Device this memory belongs to
1065 * @src: Memory region to duplicate
1066 * @len: Memory region length
1067 * @gfp: GFP mask to use
1068 *
1069 * Duplicate region of a memory using resource managed kmalloc
1070 */
1071void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
1072{
1073 void *p;
1074
1075 p = devm_kmalloc(dev, len, gfp);
1076 if (p)
1077 memcpy(p, src, len);
1078
1079 return p;
1080}
1081EXPORT_SYMBOL_GPL(devm_kmemdup);
1082
1083struct pages_devres {
1084 unsigned long addr;
1085 unsigned int order;
1086};
1087
1088static int devm_pages_match(struct device *dev, void *res, void *p)
1089{
1090 struct pages_devres *devres = res;
1091 struct pages_devres *target = p;
1092
1093 return devres->addr == target->addr;
1094}
1095
1096static void devm_pages_release(struct device *dev, void *res)
1097{
1098 struct pages_devres *devres = res;
1099
1100 free_pages(devres->addr, devres->order);
1101}
1102
1103/**
1104 * devm_get_free_pages - Resource-managed __get_free_pages
1105 * @dev: Device to allocate memory for
1106 * @gfp_mask: Allocation gfp flags
1107 * @order: Allocation size is (1 << order) pages
1108 *
1109 * Managed get_free_pages. Memory allocated with this function is
1110 * automatically freed on driver detach.
1111 *
1112 * RETURNS:
1113 * Address of allocated memory on success, 0 on failure.
1114 */
1115
1116unsigned long devm_get_free_pages(struct device *dev,
1117 gfp_t gfp_mask, unsigned int order)
1118{
1119 struct pages_devres *devres;
1120 unsigned long addr;
1121
1122 addr = __get_free_pages(gfp_mask, order);
1123
1124 if (unlikely(!addr))
1125 return 0;
1126
1127 devres = devres_alloc(devm_pages_release,
1128 sizeof(struct pages_devres), GFP_KERNEL);
1129 if (unlikely(!devres)) {
1130 free_pages(addr, order);
1131 return 0;
1132 }
1133
1134 devres->addr = addr;
1135 devres->order = order;
1136
1137 devres_add(dev, devres);
1138 return addr;
1139}
1140EXPORT_SYMBOL_GPL(devm_get_free_pages);
1141
1142/**
1143 * devm_free_pages - Resource-managed free_pages
1144 * @dev: Device this memory belongs to
1145 * @addr: Memory to free
1146 *
1147 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
1148 * there is no need to supply the @order.
1149 */
1150void devm_free_pages(struct device *dev, unsigned long addr)
1151{
1152 struct pages_devres devres = { .addr = addr };
1153
1154 WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
1155 &devres));
1156}
1157EXPORT_SYMBOL_GPL(devm_free_pages);
1158
1159static void devm_percpu_release(struct device *dev, void *pdata)
1160{
1161 void __percpu *p;
1162
1163 p = *(void __percpu **)pdata;
1164 free_percpu(p);
1165}
1166
1167static int devm_percpu_match(struct device *dev, void *data, void *p)
1168{
1169 struct devres *devr = container_of(data, struct devres, data);
1170
1171 return *(void **)devr->data == p;
1172}
1173
1174/**
1175 * __devm_alloc_percpu - Resource-managed alloc_percpu
1176 * @dev: Device to allocate per-cpu memory for
1177 * @size: Size of per-cpu memory to allocate
1178 * @align: Alignment of per-cpu memory to allocate
1179 *
1180 * Managed alloc_percpu. Per-cpu memory allocated with this function is
1181 * automatically freed on driver detach.
1182 *
1183 * RETURNS:
1184 * Pointer to allocated memory on success, NULL on failure.
1185 */
1186void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1187 size_t align)
1188{
1189 void *p;
1190 void __percpu *pcpu;
1191
1192 pcpu = __alloc_percpu(size, align);
1193 if (!pcpu)
1194 return NULL;
1195
1196 p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1197 if (!p) {
1198 free_percpu(pcpu);
1199 return NULL;
1200 }
1201
1202 *(void __percpu **)p = pcpu;
1203
1204 devres_add(dev, p);
1205
1206 return pcpu;
1207}
1208EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1209
1210/**
1211 * devm_free_percpu - Resource-managed free_percpu
1212 * @dev: Device this memory belongs to
1213 * @pdata: Per-cpu memory to free
1214 *
1215 * Free memory allocated with devm_alloc_percpu().
1216 */
1217void devm_free_percpu(struct device *dev, void __percpu *pdata)
1218{
1219 WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
1220 (__force void *)pdata));
1221}
1222EXPORT_SYMBOL_GPL(devm_free_percpu);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/base/devres.c - device resource management
4 *
5 * Copyright (c) 2006 SUSE Linux Products GmbH
6 * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
7 */
8
9#include <linux/device.h>
10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/percpu.h>
13
14#include "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);
988
989static void devm_percpu_release(struct device *dev, void *pdata)
990{
991 void __percpu *p;
992
993 p = *(void __percpu **)pdata;
994 free_percpu(p);
995}
996
997static int devm_percpu_match(struct device *dev, void *data, void *p)
998{
999 struct devres *devr = container_of(data, struct devres, data);
1000
1001 return *(void **)devr->data == p;
1002}
1003
1004/**
1005 * __devm_alloc_percpu - Resource-managed alloc_percpu
1006 * @dev: Device to allocate per-cpu memory for
1007 * @size: Size of per-cpu memory to allocate
1008 * @align: Alignment of per-cpu memory to allocate
1009 *
1010 * Managed alloc_percpu. Per-cpu memory allocated with this function is
1011 * automatically freed on driver detach.
1012 *
1013 * RETURNS:
1014 * Pointer to allocated memory on success, NULL on failure.
1015 */
1016void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1017 size_t align)
1018{
1019 void *p;
1020 void __percpu *pcpu;
1021
1022 pcpu = __alloc_percpu(size, align);
1023 if (!pcpu)
1024 return NULL;
1025
1026 p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1027 if (!p) {
1028 free_percpu(pcpu);
1029 return NULL;
1030 }
1031
1032 *(void __percpu **)p = pcpu;
1033
1034 devres_add(dev, p);
1035
1036 return pcpu;
1037}
1038EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1039
1040/**
1041 * devm_free_percpu - Resource-managed free_percpu
1042 * @dev: Device this memory belongs to
1043 * @pdata: Per-cpu memory to free
1044 *
1045 * Free memory allocated with devm_alloc_percpu().
1046 */
1047void devm_free_percpu(struct device *dev, void __percpu *pdata)
1048{
1049 WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
1050 (void *)pdata));
1051}
1052EXPORT_SYMBOL_GPL(devm_free_percpu);