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1/*
2 * drivers/base/devres.c - device resource management
3 *
4 * Copyright (c) 2006 SUSE Linux Products GmbH
5 * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
6 *
7 * This file is released under the GPLv2.
8 */
9
10#include <linux/device.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13
14#include "base.h"
15
16struct devres_node {
17 struct list_head entry;
18 dr_release_t release;
19#ifdef CONFIG_DEBUG_DEVRES
20 const char *name;
21 size_t size;
22#endif
23};
24
25struct devres {
26 struct devres_node node;
27 /* -- 3 pointers */
28 unsigned long long data[]; /* guarantee ull alignment */
29};
30
31struct devres_group {
32 struct devres_node node[2];
33 void *id;
34 int color;
35 /* -- 8 pointers */
36};
37
38#ifdef CONFIG_DEBUG_DEVRES
39static int log_devres = 0;
40module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
41
42static void set_node_dbginfo(struct devres_node *node, const char *name,
43 size_t size)
44{
45 node->name = name;
46 node->size = size;
47}
48
49static void devres_log(struct device *dev, struct devres_node *node,
50 const char *op)
51{
52 if (unlikely(log_devres))
53 dev_err(dev, "DEVRES %3s %p %s (%lu bytes)\n",
54 op, node, node->name, (unsigned long)node->size);
55}
56#else /* CONFIG_DEBUG_DEVRES */
57#define set_node_dbginfo(node, n, s) do {} while (0)
58#define devres_log(dev, node, op) do {} while (0)
59#endif /* CONFIG_DEBUG_DEVRES */
60
61/*
62 * Release functions for devres group. These callbacks are used only
63 * for identification.
64 */
65static void group_open_release(struct device *dev, void *res)
66{
67 /* noop */
68}
69
70static void group_close_release(struct device *dev, void *res)
71{
72 /* noop */
73}
74
75static struct devres_group * node_to_group(struct devres_node *node)
76{
77 if (node->release == &group_open_release)
78 return container_of(node, struct devres_group, node[0]);
79 if (node->release == &group_close_release)
80 return container_of(node, struct devres_group, node[1]);
81 return NULL;
82}
83
84static __always_inline struct devres * alloc_dr(dr_release_t release,
85 size_t size, gfp_t gfp, int nid)
86{
87 size_t tot_size = sizeof(struct devres) + size;
88 struct devres *dr;
89
90 dr = kmalloc_node_track_caller(tot_size, gfp, nid);
91 if (unlikely(!dr))
92 return NULL;
93
94 memset(dr, 0, offsetof(struct devres, data));
95
96 INIT_LIST_HEAD(&dr->node.entry);
97 dr->node.release = release;
98 return dr;
99}
100
101static void add_dr(struct device *dev, struct devres_node *node)
102{
103 devres_log(dev, node, "ADD");
104 BUG_ON(!list_empty(&node->entry));
105 list_add_tail(&node->entry, &dev->devres_head);
106}
107
108#ifdef CONFIG_DEBUG_DEVRES
109void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
110 const char *name)
111{
112 struct devres *dr;
113
114 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
115 if (unlikely(!dr))
116 return NULL;
117 set_node_dbginfo(&dr->node, name, size);
118 return dr->data;
119}
120EXPORT_SYMBOL_GPL(__devres_alloc_node);
121#else
122/**
123 * devres_alloc - Allocate device resource data
124 * @release: Release function devres will be associated with
125 * @size: Allocation size
126 * @gfp: Allocation flags
127 * @nid: NUMA node
128 *
129 * Allocate devres of @size bytes. The allocated area is zeroed, then
130 * associated with @release. The returned pointer can be passed to
131 * other devres_*() functions.
132 *
133 * RETURNS:
134 * Pointer to allocated devres on success, NULL on failure.
135 */
136void * devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid)
137{
138 struct devres *dr;
139
140 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
141 if (unlikely(!dr))
142 return NULL;
143 return dr->data;
144}
145EXPORT_SYMBOL_GPL(devres_alloc_node);
146#endif
147
148/**
149 * devres_for_each_res - Resource iterator
150 * @dev: Device to iterate resource from
151 * @release: Look for resources associated with this release function
152 * @match: Match function (optional)
153 * @match_data: Data for the match function
154 * @fn: Function to be called for each matched resource.
155 * @data: Data for @fn, the 3rd parameter of @fn
156 *
157 * Call @fn for each devres of @dev which is associated with @release
158 * and for which @match returns 1.
159 *
160 * RETURNS:
161 * void
162 */
163void devres_for_each_res(struct device *dev, dr_release_t release,
164 dr_match_t match, void *match_data,
165 void (*fn)(struct device *, void *, void *),
166 void *data)
167{
168 struct devres_node *node;
169 struct devres_node *tmp;
170 unsigned long flags;
171
172 if (!fn)
173 return;
174
175 spin_lock_irqsave(&dev->devres_lock, flags);
176 list_for_each_entry_safe_reverse(node, tmp,
177 &dev->devres_head, entry) {
178 struct devres *dr = container_of(node, struct devres, node);
179
180 if (node->release != release)
181 continue;
182 if (match && !match(dev, dr->data, match_data))
183 continue;
184 fn(dev, dr->data, data);
185 }
186 spin_unlock_irqrestore(&dev->devres_lock, flags);
187}
188EXPORT_SYMBOL_GPL(devres_for_each_res);
189
190/**
191 * devres_free - Free device resource data
192 * @res: Pointer to devres data to free
193 *
194 * Free devres created with devres_alloc().
195 */
196void devres_free(void *res)
197{
198 if (res) {
199 struct devres *dr = container_of(res, struct devres, data);
200
201 BUG_ON(!list_empty(&dr->node.entry));
202 kfree(dr);
203 }
204}
205EXPORT_SYMBOL_GPL(devres_free);
206
207/**
208 * devres_add - Register device resource
209 * @dev: Device to add resource to
210 * @res: Resource to register
211 *
212 * Register devres @res to @dev. @res should have been allocated
213 * using devres_alloc(). On driver detach, the associated release
214 * function will be invoked and devres will be freed automatically.
215 */
216void devres_add(struct device *dev, void *res)
217{
218 struct devres *dr = container_of(res, struct devres, data);
219 unsigned long flags;
220
221 spin_lock_irqsave(&dev->devres_lock, flags);
222 add_dr(dev, &dr->node);
223 spin_unlock_irqrestore(&dev->devres_lock, flags);
224}
225EXPORT_SYMBOL_GPL(devres_add);
226
227static struct devres *find_dr(struct device *dev, dr_release_t release,
228 dr_match_t match, void *match_data)
229{
230 struct devres_node *node;
231
232 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
233 struct devres *dr = container_of(node, struct devres, node);
234
235 if (node->release != release)
236 continue;
237 if (match && !match(dev, dr->data, match_data))
238 continue;
239 return dr;
240 }
241
242 return NULL;
243}
244
245/**
246 * devres_find - Find device resource
247 * @dev: Device to lookup resource from
248 * @release: Look for resources associated with this release function
249 * @match: Match function (optional)
250 * @match_data: Data for the match function
251 *
252 * Find the latest devres of @dev which is associated with @release
253 * and for which @match returns 1. If @match is NULL, it's considered
254 * to match all.
255 *
256 * RETURNS:
257 * Pointer to found devres, NULL if not found.
258 */
259void * devres_find(struct device *dev, dr_release_t release,
260 dr_match_t match, void *match_data)
261{
262 struct devres *dr;
263 unsigned long flags;
264
265 spin_lock_irqsave(&dev->devres_lock, flags);
266 dr = find_dr(dev, release, match, match_data);
267 spin_unlock_irqrestore(&dev->devres_lock, flags);
268
269 if (dr)
270 return dr->data;
271 return NULL;
272}
273EXPORT_SYMBOL_GPL(devres_find);
274
275/**
276 * devres_get - Find devres, if non-existent, add one atomically
277 * @dev: Device to lookup or add devres for
278 * @new_res: Pointer to new initialized devres to add if not found
279 * @match: Match function (optional)
280 * @match_data: Data for the match function
281 *
282 * Find the latest devres of @dev which has the same release function
283 * as @new_res and for which @match return 1. If found, @new_res is
284 * freed; otherwise, @new_res is added atomically.
285 *
286 * RETURNS:
287 * Pointer to found or added devres.
288 */
289void * devres_get(struct device *dev, void *new_res,
290 dr_match_t match, void *match_data)
291{
292 struct devres *new_dr = container_of(new_res, struct devres, data);
293 struct devres *dr;
294 unsigned long flags;
295
296 spin_lock_irqsave(&dev->devres_lock, flags);
297 dr = find_dr(dev, new_dr->node.release, match, match_data);
298 if (!dr) {
299 add_dr(dev, &new_dr->node);
300 dr = new_dr;
301 new_res = NULL;
302 }
303 spin_unlock_irqrestore(&dev->devres_lock, flags);
304 devres_free(new_res);
305
306 return dr->data;
307}
308EXPORT_SYMBOL_GPL(devres_get);
309
310/**
311 * devres_remove - Find a device resource and remove it
312 * @dev: Device to find resource from
313 * @release: Look for resources associated with this release function
314 * @match: Match function (optional)
315 * @match_data: Data for the match function
316 *
317 * Find the latest devres of @dev associated with @release and for
318 * which @match returns 1. If @match is NULL, it's considered to
319 * match all. If found, the resource is removed atomically and
320 * returned.
321 *
322 * RETURNS:
323 * Pointer to removed devres on success, NULL if not found.
324 */
325void * devres_remove(struct device *dev, dr_release_t release,
326 dr_match_t match, void *match_data)
327{
328 struct devres *dr;
329 unsigned long flags;
330
331 spin_lock_irqsave(&dev->devres_lock, flags);
332 dr = find_dr(dev, release, match, match_data);
333 if (dr) {
334 list_del_init(&dr->node.entry);
335 devres_log(dev, &dr->node, "REM");
336 }
337 spin_unlock_irqrestore(&dev->devres_lock, flags);
338
339 if (dr)
340 return dr->data;
341 return NULL;
342}
343EXPORT_SYMBOL_GPL(devres_remove);
344
345/**
346 * devres_destroy - Find a device resource and destroy it
347 * @dev: Device to find resource from
348 * @release: Look for resources associated with this release function
349 * @match: Match function (optional)
350 * @match_data: Data for the match function
351 *
352 * Find the latest devres of @dev associated with @release and for
353 * which @match returns 1. If @match is NULL, it's considered to
354 * match all. If found, the resource is removed atomically and freed.
355 *
356 * Note that the release function for the resource will not be called,
357 * only the devres-allocated data will be freed. The caller becomes
358 * responsible for freeing any other data.
359 *
360 * RETURNS:
361 * 0 if devres is found and freed, -ENOENT if not found.
362 */
363int devres_destroy(struct device *dev, dr_release_t release,
364 dr_match_t match, void *match_data)
365{
366 void *res;
367
368 res = devres_remove(dev, release, match, match_data);
369 if (unlikely(!res))
370 return -ENOENT;
371
372 devres_free(res);
373 return 0;
374}
375EXPORT_SYMBOL_GPL(devres_destroy);
376
377
378/**
379 * devres_release - Find a device resource and destroy it, calling release
380 * @dev: Device to find resource from
381 * @release: Look for resources associated with this release function
382 * @match: Match function (optional)
383 * @match_data: Data for the match function
384 *
385 * Find the latest devres of @dev associated with @release and for
386 * which @match returns 1. If @match is NULL, it's considered to
387 * match all. If found, the resource is removed atomically, the
388 * release function called and the resource freed.
389 *
390 * RETURNS:
391 * 0 if devres is found and freed, -ENOENT if not found.
392 */
393int devres_release(struct device *dev, dr_release_t release,
394 dr_match_t match, void *match_data)
395{
396 void *res;
397
398 res = devres_remove(dev, release, match, match_data);
399 if (unlikely(!res))
400 return -ENOENT;
401
402 (*release)(dev, res);
403 devres_free(res);
404 return 0;
405}
406EXPORT_SYMBOL_GPL(devres_release);
407
408static int remove_nodes(struct device *dev,
409 struct list_head *first, struct list_head *end,
410 struct list_head *todo)
411{
412 int cnt = 0, nr_groups = 0;
413 struct list_head *cur;
414
415 /* First pass - move normal devres entries to @todo and clear
416 * devres_group colors.
417 */
418 cur = first;
419 while (cur != end) {
420 struct devres_node *node;
421 struct devres_group *grp;
422
423 node = list_entry(cur, struct devres_node, entry);
424 cur = cur->next;
425
426 grp = node_to_group(node);
427 if (grp) {
428 /* clear color of group markers in the first pass */
429 grp->color = 0;
430 nr_groups++;
431 } else {
432 /* regular devres entry */
433 if (&node->entry == first)
434 first = first->next;
435 list_move_tail(&node->entry, todo);
436 cnt++;
437 }
438 }
439
440 if (!nr_groups)
441 return cnt;
442
443 /* Second pass - Scan groups and color them. A group gets
444 * color value of two iff the group is wholly contained in
445 * [cur, end). That is, for a closed group, both opening and
446 * closing markers should be in the range, while just the
447 * opening marker is enough for an open group.
448 */
449 cur = first;
450 while (cur != end) {
451 struct devres_node *node;
452 struct devres_group *grp;
453
454 node = list_entry(cur, struct devres_node, entry);
455 cur = cur->next;
456
457 grp = node_to_group(node);
458 BUG_ON(!grp || list_empty(&grp->node[0].entry));
459
460 grp->color++;
461 if (list_empty(&grp->node[1].entry))
462 grp->color++;
463
464 BUG_ON(grp->color <= 0 || grp->color > 2);
465 if (grp->color == 2) {
466 /* No need to update cur or end. The removed
467 * nodes are always before both.
468 */
469 list_move_tail(&grp->node[0].entry, todo);
470 list_del_init(&grp->node[1].entry);
471 }
472 }
473
474 return cnt;
475}
476
477static int release_nodes(struct device *dev, struct list_head *first,
478 struct list_head *end, unsigned long flags)
479 __releases(&dev->devres_lock)
480{
481 LIST_HEAD(todo);
482 int cnt;
483 struct devres *dr, *tmp;
484
485 cnt = remove_nodes(dev, first, end, &todo);
486
487 spin_unlock_irqrestore(&dev->devres_lock, flags);
488
489 /* Release. Note that both devres and devres_group are
490 * handled as devres in the following loop. This is safe.
491 */
492 list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
493 devres_log(dev, &dr->node, "REL");
494 dr->node.release(dev, dr->data);
495 kfree(dr);
496 }
497
498 return cnt;
499}
500
501/**
502 * devres_release_all - Release all managed resources
503 * @dev: Device to release resources for
504 *
505 * Release all resources associated with @dev. This function is
506 * called on driver detach.
507 */
508int devres_release_all(struct device *dev)
509{
510 unsigned long flags;
511
512 /* Looks like an uninitialized device structure */
513 if (WARN_ON(dev->devres_head.next == NULL))
514 return -ENODEV;
515 spin_lock_irqsave(&dev->devres_lock, flags);
516 return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
517 flags);
518}
519
520/**
521 * devres_open_group - Open a new devres group
522 * @dev: Device to open devres group for
523 * @id: Separator ID
524 * @gfp: Allocation flags
525 *
526 * Open a new devres group for @dev with @id. For @id, using a
527 * pointer to an object which won't be used for another group is
528 * recommended. If @id is NULL, address-wise unique ID is created.
529 *
530 * RETURNS:
531 * ID of the new group, NULL on failure.
532 */
533void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
534{
535 struct devres_group *grp;
536 unsigned long flags;
537
538 grp = kmalloc(sizeof(*grp), gfp);
539 if (unlikely(!grp))
540 return NULL;
541
542 grp->node[0].release = &group_open_release;
543 grp->node[1].release = &group_close_release;
544 INIT_LIST_HEAD(&grp->node[0].entry);
545 INIT_LIST_HEAD(&grp->node[1].entry);
546 set_node_dbginfo(&grp->node[0], "grp<", 0);
547 set_node_dbginfo(&grp->node[1], "grp>", 0);
548 grp->id = grp;
549 if (id)
550 grp->id = id;
551
552 spin_lock_irqsave(&dev->devres_lock, flags);
553 add_dr(dev, &grp->node[0]);
554 spin_unlock_irqrestore(&dev->devres_lock, flags);
555 return grp->id;
556}
557EXPORT_SYMBOL_GPL(devres_open_group);
558
559/* Find devres group with ID @id. If @id is NULL, look for the latest. */
560static struct devres_group * find_group(struct device *dev, void *id)
561{
562 struct devres_node *node;
563
564 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
565 struct devres_group *grp;
566
567 if (node->release != &group_open_release)
568 continue;
569
570 grp = container_of(node, struct devres_group, node[0]);
571
572 if (id) {
573 if (grp->id == id)
574 return grp;
575 } else if (list_empty(&grp->node[1].entry))
576 return grp;
577 }
578
579 return NULL;
580}
581
582/**
583 * devres_close_group - Close a devres group
584 * @dev: Device to close devres group for
585 * @id: ID of target group, can be NULL
586 *
587 * Close the group identified by @id. If @id is NULL, the latest open
588 * group is selected.
589 */
590void devres_close_group(struct device *dev, void *id)
591{
592 struct devres_group *grp;
593 unsigned long flags;
594
595 spin_lock_irqsave(&dev->devres_lock, flags);
596
597 grp = find_group(dev, id);
598 if (grp)
599 add_dr(dev, &grp->node[1]);
600 else
601 WARN_ON(1);
602
603 spin_unlock_irqrestore(&dev->devres_lock, flags);
604}
605EXPORT_SYMBOL_GPL(devres_close_group);
606
607/**
608 * devres_remove_group - Remove a devres group
609 * @dev: Device to remove group for
610 * @id: ID of target group, can be NULL
611 *
612 * Remove the group identified by @id. If @id is NULL, the latest
613 * open group is selected. Note that removing a group doesn't affect
614 * any other resources.
615 */
616void devres_remove_group(struct device *dev, void *id)
617{
618 struct devres_group *grp;
619 unsigned long flags;
620
621 spin_lock_irqsave(&dev->devres_lock, flags);
622
623 grp = find_group(dev, id);
624 if (grp) {
625 list_del_init(&grp->node[0].entry);
626 list_del_init(&grp->node[1].entry);
627 devres_log(dev, &grp->node[0], "REM");
628 } else
629 WARN_ON(1);
630
631 spin_unlock_irqrestore(&dev->devres_lock, flags);
632
633 kfree(grp);
634}
635EXPORT_SYMBOL_GPL(devres_remove_group);
636
637/**
638 * devres_release_group - Release resources in a devres group
639 * @dev: Device to release group for
640 * @id: ID of target group, can be NULL
641 *
642 * Release all resources in the group identified by @id. If @id is
643 * NULL, the latest open group is selected. The selected group and
644 * groups properly nested inside the selected group are removed.
645 *
646 * RETURNS:
647 * The number of released non-group resources.
648 */
649int devres_release_group(struct device *dev, void *id)
650{
651 struct devres_group *grp;
652 unsigned long flags;
653 int cnt = 0;
654
655 spin_lock_irqsave(&dev->devres_lock, flags);
656
657 grp = find_group(dev, id);
658 if (grp) {
659 struct list_head *first = &grp->node[0].entry;
660 struct list_head *end = &dev->devres_head;
661
662 if (!list_empty(&grp->node[1].entry))
663 end = grp->node[1].entry.next;
664
665 cnt = release_nodes(dev, first, end, flags);
666 } else {
667 WARN_ON(1);
668 spin_unlock_irqrestore(&dev->devres_lock, flags);
669 }
670
671 return cnt;
672}
673EXPORT_SYMBOL_GPL(devres_release_group);
674
675/*
676 * Custom devres actions allow inserting a simple function call
677 * into the teadown sequence.
678 */
679
680struct action_devres {
681 void *data;
682 void (*action)(void *);
683};
684
685static int devm_action_match(struct device *dev, void *res, void *p)
686{
687 struct action_devres *devres = res;
688 struct action_devres *target = p;
689
690 return devres->action == target->action &&
691 devres->data == target->data;
692}
693
694static void devm_action_release(struct device *dev, void *res)
695{
696 struct action_devres *devres = res;
697
698 devres->action(devres->data);
699}
700
701/**
702 * devm_add_action() - add a custom action to list of managed resources
703 * @dev: Device that owns the action
704 * @action: Function that should be called
705 * @data: Pointer to data passed to @action implementation
706 *
707 * This adds a custom action to the list of managed resources so that
708 * it gets executed as part of standard resource unwinding.
709 */
710int devm_add_action(struct device *dev, void (*action)(void *), void *data)
711{
712 struct action_devres *devres;
713
714 devres = devres_alloc(devm_action_release,
715 sizeof(struct action_devres), GFP_KERNEL);
716 if (!devres)
717 return -ENOMEM;
718
719 devres->data = data;
720 devres->action = action;
721
722 devres_add(dev, devres);
723 return 0;
724}
725EXPORT_SYMBOL_GPL(devm_add_action);
726
727/**
728 * devm_remove_action() - removes previously added custom action
729 * @dev: Device that owns the action
730 * @action: Function implementing the action
731 * @data: Pointer to data passed to @action implementation
732 *
733 * Removes instance of @action previously added by devm_add_action().
734 * Both action and data should match one of the existing entries.
735 */
736void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
737{
738 struct action_devres devres = {
739 .data = data,
740 .action = action,
741 };
742
743 WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
744 &devres));
745
746}
747EXPORT_SYMBOL_GPL(devm_remove_action);
748
749/*
750 * Managed kmalloc/kfree
751 */
752static void devm_kmalloc_release(struct device *dev, void *res)
753{
754 /* noop */
755}
756
757static int devm_kmalloc_match(struct device *dev, void *res, void *data)
758{
759 return res == data;
760}
761
762/**
763 * devm_kmalloc - Resource-managed kmalloc
764 * @dev: Device to allocate memory for
765 * @size: Allocation size
766 * @gfp: Allocation gfp flags
767 *
768 * Managed kmalloc. Memory allocated with this function is
769 * automatically freed on driver detach. Like all other devres
770 * resources, guaranteed alignment is unsigned long long.
771 *
772 * RETURNS:
773 * Pointer to allocated memory on success, NULL on failure.
774 */
775void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
776{
777 struct devres *dr;
778
779 /* use raw alloc_dr for kmalloc caller tracing */
780 dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
781 if (unlikely(!dr))
782 return NULL;
783
784 /*
785 * This is named devm_kzalloc_release for historical reasons
786 * The initial implementation did not support kmalloc, only kzalloc
787 */
788 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
789 devres_add(dev, dr->data);
790 return dr->data;
791}
792EXPORT_SYMBOL_GPL(devm_kmalloc);
793
794/**
795 * devm_kstrdup - Allocate resource managed space and
796 * copy an existing string into that.
797 * @dev: Device to allocate memory for
798 * @s: the string to duplicate
799 * @gfp: the GFP mask used in the devm_kmalloc() call when
800 * allocating memory
801 * RETURNS:
802 * Pointer to allocated string on success, NULL on failure.
803 */
804char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
805{
806 size_t size;
807 char *buf;
808
809 if (!s)
810 return NULL;
811
812 size = strlen(s) + 1;
813 buf = devm_kmalloc(dev, size, gfp);
814 if (buf)
815 memcpy(buf, s, size);
816 return buf;
817}
818EXPORT_SYMBOL_GPL(devm_kstrdup);
819
820/**
821 * devm_kvasprintf - Allocate resource managed space and format a string
822 * into that.
823 * @dev: Device to allocate memory for
824 * @gfp: the GFP mask used in the devm_kmalloc() call when
825 * allocating memory
826 * @fmt: The printf()-style format string
827 * @ap: Arguments for the format string
828 * RETURNS:
829 * Pointer to allocated string on success, NULL on failure.
830 */
831char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
832 va_list ap)
833{
834 unsigned int len;
835 char *p;
836 va_list aq;
837
838 va_copy(aq, ap);
839 len = vsnprintf(NULL, 0, fmt, aq);
840 va_end(aq);
841
842 p = devm_kmalloc(dev, len+1, gfp);
843 if (!p)
844 return NULL;
845
846 vsnprintf(p, len+1, fmt, ap);
847
848 return p;
849}
850EXPORT_SYMBOL(devm_kvasprintf);
851
852/**
853 * devm_kasprintf - Allocate resource managed space and format a string
854 * into that.
855 * @dev: Device to allocate memory for
856 * @gfp: the GFP mask used in the devm_kmalloc() call when
857 * allocating memory
858 * @fmt: The printf()-style format string
859 * @...: Arguments for the format string
860 * RETURNS:
861 * Pointer to allocated string on success, NULL on failure.
862 */
863char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
864{
865 va_list ap;
866 char *p;
867
868 va_start(ap, fmt);
869 p = devm_kvasprintf(dev, gfp, fmt, ap);
870 va_end(ap);
871
872 return p;
873}
874EXPORT_SYMBOL_GPL(devm_kasprintf);
875
876/**
877 * devm_kfree - Resource-managed kfree
878 * @dev: Device this memory belongs to
879 * @p: Memory to free
880 *
881 * Free memory allocated with devm_kmalloc().
882 */
883void devm_kfree(struct device *dev, void *p)
884{
885 int rc;
886
887 rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);
888 WARN_ON(rc);
889}
890EXPORT_SYMBOL_GPL(devm_kfree);
891
892/**
893 * devm_kmemdup - Resource-managed kmemdup
894 * @dev: Device this memory belongs to
895 * @src: Memory region to duplicate
896 * @len: Memory region length
897 * @gfp: GFP mask to use
898 *
899 * Duplicate region of a memory using resource managed kmalloc
900 */
901void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
902{
903 void *p;
904
905 p = devm_kmalloc(dev, len, gfp);
906 if (p)
907 memcpy(p, src, len);
908
909 return p;
910}
911EXPORT_SYMBOL_GPL(devm_kmemdup);
912
913struct pages_devres {
914 unsigned long addr;
915 unsigned int order;
916};
917
918static int devm_pages_match(struct device *dev, void *res, void *p)
919{
920 struct pages_devres *devres = res;
921 struct pages_devres *target = p;
922
923 return devres->addr == target->addr;
924}
925
926static void devm_pages_release(struct device *dev, void *res)
927{
928 struct pages_devres *devres = res;
929
930 free_pages(devres->addr, devres->order);
931}
932
933/**
934 * devm_get_free_pages - Resource-managed __get_free_pages
935 * @dev: Device to allocate memory for
936 * @gfp_mask: Allocation gfp flags
937 * @order: Allocation size is (1 << order) pages
938 *
939 * Managed get_free_pages. Memory allocated with this function is
940 * automatically freed on driver detach.
941 *
942 * RETURNS:
943 * Address of allocated memory on success, 0 on failure.
944 */
945
946unsigned long devm_get_free_pages(struct device *dev,
947 gfp_t gfp_mask, unsigned int order)
948{
949 struct pages_devres *devres;
950 unsigned long addr;
951
952 addr = __get_free_pages(gfp_mask, order);
953
954 if (unlikely(!addr))
955 return 0;
956
957 devres = devres_alloc(devm_pages_release,
958 sizeof(struct pages_devres), GFP_KERNEL);
959 if (unlikely(!devres)) {
960 free_pages(addr, order);
961 return 0;
962 }
963
964 devres->addr = addr;
965 devres->order = order;
966
967 devres_add(dev, devres);
968 return addr;
969}
970EXPORT_SYMBOL_GPL(devm_get_free_pages);
971
972/**
973 * devm_free_pages - Resource-managed free_pages
974 * @dev: Device this memory belongs to
975 * @addr: Memory to free
976 *
977 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
978 * there is no need to supply the @order.
979 */
980void devm_free_pages(struct device *dev, unsigned long addr)
981{
982 struct pages_devres devres = { .addr = addr };
983
984 WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
985 &devres));
986}
987EXPORT_SYMBOL_GPL(devm_free_pages);
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);