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