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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/base/devres.c - device resource management
4 *
5 * Copyright (c) 2006 SUSE Linux Products GmbH
6 * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
7 */
8
9#include <linux/device.h>
10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/percpu.h>
13
14#include <asm/sections.h>
15
16#include "base.h"
17#include "trace.h"
18
19struct devres_node {
20 struct list_head entry;
21 dr_release_t release;
22 const char *name;
23 size_t size;
24};
25
26struct devres {
27 struct devres_node node;
28 /*
29 * Some archs want to perform DMA into kmalloc caches
30 * and need a guaranteed alignment larger than
31 * the alignment of a 64-bit integer.
32 * Thus we use ARCH_DMA_MINALIGN for data[] which will force the same
33 * alignment for struct devres when allocated by kmalloc().
34 */
35 u8 __aligned(ARCH_DMA_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 /* Actually allocate the full kmalloc bucket size. */
105 *tot_size = kmalloc_size_roundup(*tot_size);
106
107 return true;
108}
109
110static __always_inline struct devres * alloc_dr(dr_release_t release,
111 size_t size, gfp_t gfp, int nid)
112{
113 size_t tot_size;
114 struct devres *dr;
115
116 if (!check_dr_size(size, &tot_size))
117 return NULL;
118
119 dr = kmalloc_node_track_caller(tot_size, gfp, nid);
120 if (unlikely(!dr))
121 return NULL;
122
123 /* No need to clear memory twice */
124 if (!(gfp & __GFP_ZERO))
125 memset(dr, 0, offsetof(struct devres, data));
126
127 INIT_LIST_HEAD(&dr->node.entry);
128 dr->node.release = release;
129 return dr;
130}
131
132static void add_dr(struct device *dev, struct devres_node *node)
133{
134 devres_log(dev, node, "ADD");
135 BUG_ON(!list_empty(&node->entry));
136 list_add_tail(&node->entry, &dev->devres_head);
137}
138
139static void replace_dr(struct device *dev,
140 struct devres_node *old, struct devres_node *new)
141{
142 devres_log(dev, old, "REPLACE");
143 BUG_ON(!list_empty(&new->entry));
144 list_replace(&old->entry, &new->entry);
145}
146
147/**
148 * __devres_alloc_node - Allocate device resource data
149 * @release: Release function devres will be associated with
150 * @size: Allocation size
151 * @gfp: Allocation flags
152 * @nid: NUMA node
153 * @name: Name of the resource
154 *
155 * Allocate devres of @size bytes. The allocated area is zeroed, then
156 * associated with @release. The returned pointer can be passed to
157 * other devres_*() functions.
158 *
159 * RETURNS:
160 * Pointer to allocated devres on success, NULL on failure.
161 */
162void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
163 const char *name)
164{
165 struct devres *dr;
166
167 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
168 if (unlikely(!dr))
169 return NULL;
170 set_node_dbginfo(&dr->node, name, size);
171 return dr->data;
172}
173EXPORT_SYMBOL_GPL(__devres_alloc_node);
174
175/**
176 * devres_for_each_res - Resource iterator
177 * @dev: Device to iterate resource from
178 * @release: Look for resources associated with this release function
179 * @match: Match function (optional)
180 * @match_data: Data for the match function
181 * @fn: Function to be called for each matched resource.
182 * @data: Data for @fn, the 3rd parameter of @fn
183 *
184 * Call @fn for each devres of @dev which is associated with @release
185 * and for which @match returns 1.
186 *
187 * RETURNS:
188 * void
189 */
190void devres_for_each_res(struct device *dev, dr_release_t release,
191 dr_match_t match, void *match_data,
192 void (*fn)(struct device *, void *, void *),
193 void *data)
194{
195 struct devres_node *node;
196 struct devres_node *tmp;
197 unsigned long flags;
198
199 if (!fn)
200 return;
201
202 spin_lock_irqsave(&dev->devres_lock, flags);
203 list_for_each_entry_safe_reverse(node, tmp,
204 &dev->devres_head, entry) {
205 struct devres *dr = container_of(node, struct devres, node);
206
207 if (node->release != release)
208 continue;
209 if (match && !match(dev, dr->data, match_data))
210 continue;
211 fn(dev, dr->data, data);
212 }
213 spin_unlock_irqrestore(&dev->devres_lock, flags);
214}
215EXPORT_SYMBOL_GPL(devres_for_each_res);
216
217/**
218 * devres_free - Free device resource data
219 * @res: Pointer to devres data to free
220 *
221 * Free devres created with devres_alloc().
222 */
223void devres_free(void *res)
224{
225 if (res) {
226 struct devres *dr = container_of(res, struct devres, data);
227
228 BUG_ON(!list_empty(&dr->node.entry));
229 kfree(dr);
230 }
231}
232EXPORT_SYMBOL_GPL(devres_free);
233
234/**
235 * devres_add - Register device resource
236 * @dev: Device to add resource to
237 * @res: Resource to register
238 *
239 * Register devres @res to @dev. @res should have been allocated
240 * using devres_alloc(). On driver detach, the associated release
241 * function will be invoked and devres will be freed automatically.
242 */
243void devres_add(struct device *dev, void *res)
244{
245 struct devres *dr = container_of(res, struct devres, data);
246 unsigned long flags;
247
248 spin_lock_irqsave(&dev->devres_lock, flags);
249 add_dr(dev, &dr->node);
250 spin_unlock_irqrestore(&dev->devres_lock, flags);
251}
252EXPORT_SYMBOL_GPL(devres_add);
253
254static struct devres *find_dr(struct device *dev, dr_release_t release,
255 dr_match_t match, void *match_data)
256{
257 struct devres_node *node;
258
259 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
260 struct devres *dr = container_of(node, struct devres, node);
261
262 if (node->release != release)
263 continue;
264 if (match && !match(dev, dr->data, match_data))
265 continue;
266 return dr;
267 }
268
269 return NULL;
270}
271
272/**
273 * devres_find - Find device resource
274 * @dev: Device to lookup resource from
275 * @release: Look for resources associated with this release function
276 * @match: Match function (optional)
277 * @match_data: Data for the match function
278 *
279 * Find the latest devres of @dev which is associated with @release
280 * and for which @match returns 1. If @match is NULL, it's considered
281 * to match all.
282 *
283 * RETURNS:
284 * Pointer to found devres, NULL if not found.
285 */
286void * devres_find(struct device *dev, dr_release_t release,
287 dr_match_t match, void *match_data)
288{
289 struct devres *dr;
290 unsigned long flags;
291
292 spin_lock_irqsave(&dev->devres_lock, flags);
293 dr = find_dr(dev, release, match, match_data);
294 spin_unlock_irqrestore(&dev->devres_lock, flags);
295
296 if (dr)
297 return dr->data;
298 return NULL;
299}
300EXPORT_SYMBOL_GPL(devres_find);
301
302/**
303 * devres_get - Find devres, if non-existent, add one atomically
304 * @dev: Device to lookup or add devres for
305 * @new_res: Pointer to new initialized devres to add if not found
306 * @match: Match function (optional)
307 * @match_data: Data for the match function
308 *
309 * Find the latest devres of @dev which has the same release function
310 * as @new_res and for which @match return 1. If found, @new_res is
311 * freed; otherwise, @new_res is added atomically.
312 *
313 * RETURNS:
314 * Pointer to found or added devres.
315 */
316void * devres_get(struct device *dev, void *new_res,
317 dr_match_t match, void *match_data)
318{
319 struct devres *new_dr = container_of(new_res, struct devres, data);
320 struct devres *dr;
321 unsigned long flags;
322
323 spin_lock_irqsave(&dev->devres_lock, flags);
324 dr = find_dr(dev, new_dr->node.release, match, match_data);
325 if (!dr) {
326 add_dr(dev, &new_dr->node);
327 dr = new_dr;
328 new_res = NULL;
329 }
330 spin_unlock_irqrestore(&dev->devres_lock, flags);
331 devres_free(new_res);
332
333 return dr->data;
334}
335EXPORT_SYMBOL_GPL(devres_get);
336
337/**
338 * devres_remove - Find a device resource and remove it
339 * @dev: Device to find resource from
340 * @release: Look for resources associated with this release function
341 * @match: Match function (optional)
342 * @match_data: Data for the match function
343 *
344 * Find the latest devres of @dev associated with @release and for
345 * which @match returns 1. If @match is NULL, it's considered to
346 * match all. If found, the resource is removed atomically and
347 * returned.
348 *
349 * RETURNS:
350 * Pointer to removed devres on success, NULL if not found.
351 */
352void * devres_remove(struct device *dev, dr_release_t release,
353 dr_match_t match, void *match_data)
354{
355 struct devres *dr;
356 unsigned long flags;
357
358 spin_lock_irqsave(&dev->devres_lock, flags);
359 dr = find_dr(dev, release, match, match_data);
360 if (dr) {
361 list_del_init(&dr->node.entry);
362 devres_log(dev, &dr->node, "REM");
363 }
364 spin_unlock_irqrestore(&dev->devres_lock, flags);
365
366 if (dr)
367 return dr->data;
368 return NULL;
369}
370EXPORT_SYMBOL_GPL(devres_remove);
371
372/**
373 * devres_destroy - Find a device resource and destroy it
374 * @dev: Device to find resource from
375 * @release: Look for resources associated with this release function
376 * @match: Match function (optional)
377 * @match_data: Data for the match function
378 *
379 * Find the latest devres of @dev associated with @release and for
380 * which @match returns 1. If @match is NULL, it's considered to
381 * match all. If found, the resource is removed atomically and freed.
382 *
383 * Note that the release function for the resource will not be called,
384 * only the devres-allocated data will be freed. The caller becomes
385 * responsible for freeing any other data.
386 *
387 * RETURNS:
388 * 0 if devres is found and freed, -ENOENT if not found.
389 */
390int devres_destroy(struct device *dev, dr_release_t release,
391 dr_match_t match, void *match_data)
392{
393 void *res;
394
395 res = devres_remove(dev, release, match, match_data);
396 if (unlikely(!res))
397 return -ENOENT;
398
399 devres_free(res);
400 return 0;
401}
402EXPORT_SYMBOL_GPL(devres_destroy);
403
404
405/**
406 * devres_release - Find a device resource and destroy it, calling release
407 * @dev: Device to find resource from
408 * @release: Look for resources associated with this release function
409 * @match: Match function (optional)
410 * @match_data: Data for the match function
411 *
412 * Find the latest devres of @dev associated with @release and for
413 * which @match returns 1. If @match is NULL, it's considered to
414 * match all. If found, the resource is removed atomically, the
415 * release function called and the resource freed.
416 *
417 * RETURNS:
418 * 0 if devres is found and freed, -ENOENT if not found.
419 */
420int devres_release(struct device *dev, dr_release_t release,
421 dr_match_t match, void *match_data)
422{
423 void *res;
424
425 res = devres_remove(dev, release, match, match_data);
426 if (unlikely(!res))
427 return -ENOENT;
428
429 (*release)(dev, res);
430 devres_free(res);
431 return 0;
432}
433EXPORT_SYMBOL_GPL(devres_release);
434
435static int remove_nodes(struct device *dev,
436 struct list_head *first, struct list_head *end,
437 struct list_head *todo)
438{
439 struct devres_node *node, *n;
440 int cnt = 0, nr_groups = 0;
441
442 /* First pass - move normal devres entries to @todo and clear
443 * devres_group colors.
444 */
445 node = list_entry(first, struct devres_node, entry);
446 list_for_each_entry_safe_from(node, n, end, entry) {
447 struct devres_group *grp;
448
449 grp = node_to_group(node);
450 if (grp) {
451 /* clear color of group markers in the first pass */
452 grp->color = 0;
453 nr_groups++;
454 } else {
455 /* regular devres entry */
456 if (&node->entry == first)
457 first = first->next;
458 list_move_tail(&node->entry, todo);
459 cnt++;
460 }
461 }
462
463 if (!nr_groups)
464 return cnt;
465
466 /* Second pass - Scan groups and color them. A group gets
467 * color value of two iff the group is wholly contained in
468 * [current node, end). That is, for a closed group, both opening
469 * and closing markers should be in the range, while just the
470 * opening marker is enough for an open group.
471 */
472 node = list_entry(first, struct devres_node, entry);
473 list_for_each_entry_safe_from(node, n, end, entry) {
474 struct devres_group *grp;
475
476 grp = node_to_group(node);
477 BUG_ON(!grp || list_empty(&grp->node[0].entry));
478
479 grp->color++;
480 if (list_empty(&grp->node[1].entry))
481 grp->color++;
482
483 BUG_ON(grp->color <= 0 || grp->color > 2);
484 if (grp->color == 2) {
485 /* No need to update current node or end. The removed
486 * nodes are always before both.
487 */
488 list_move_tail(&grp->node[0].entry, todo);
489 list_del_init(&grp->node[1].entry);
490 }
491 }
492
493 return cnt;
494}
495
496static void release_nodes(struct device *dev, struct list_head *todo)
497{
498 struct devres *dr, *tmp;
499
500 /* Release. Note that both devres and devres_group are
501 * handled as devres in the following loop. This is safe.
502 */
503 list_for_each_entry_safe_reverse(dr, tmp, todo, node.entry) {
504 devres_log(dev, &dr->node, "REL");
505 dr->node.release(dev, dr->data);
506 kfree(dr);
507 }
508}
509
510/**
511 * devres_release_all - Release all managed resources
512 * @dev: Device to release resources for
513 *
514 * Release all resources associated with @dev. This function is
515 * called on driver detach.
516 */
517int devres_release_all(struct device *dev)
518{
519 unsigned long flags;
520 LIST_HEAD(todo);
521 int cnt;
522
523 /* Looks like an uninitialized device structure */
524 if (WARN_ON(dev->devres_head.next == NULL))
525 return -ENODEV;
526
527 /* Nothing to release if list is empty */
528 if (list_empty(&dev->devres_head))
529 return 0;
530
531 spin_lock_irqsave(&dev->devres_lock, flags);
532 cnt = remove_nodes(dev, dev->devres_head.next, &dev->devres_head, &todo);
533 spin_unlock_irqrestore(&dev->devres_lock, flags);
534
535 release_nodes(dev, &todo);
536 return cnt;
537}
538
539/**
540 * devres_open_group - Open a new devres group
541 * @dev: Device to open devres group for
542 * @id: Separator ID
543 * @gfp: Allocation flags
544 *
545 * Open a new devres group for @dev with @id. For @id, using a
546 * pointer to an object which won't be used for another group is
547 * recommended. If @id is NULL, address-wise unique ID is created.
548 *
549 * RETURNS:
550 * ID of the new group, NULL on failure.
551 */
552void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
553{
554 struct devres_group *grp;
555 unsigned long flags;
556
557 grp = kmalloc(sizeof(*grp), gfp);
558 if (unlikely(!grp))
559 return NULL;
560
561 grp->node[0].release = &group_open_release;
562 grp->node[1].release = &group_close_release;
563 INIT_LIST_HEAD(&grp->node[0].entry);
564 INIT_LIST_HEAD(&grp->node[1].entry);
565 set_node_dbginfo(&grp->node[0], "grp<", 0);
566 set_node_dbginfo(&grp->node[1], "grp>", 0);
567 grp->id = grp;
568 if (id)
569 grp->id = id;
570
571 spin_lock_irqsave(&dev->devres_lock, flags);
572 add_dr(dev, &grp->node[0]);
573 spin_unlock_irqrestore(&dev->devres_lock, flags);
574 return grp->id;
575}
576EXPORT_SYMBOL_GPL(devres_open_group);
577
578/* Find devres group with ID @id. If @id is NULL, look for the latest. */
579static struct devres_group * find_group(struct device *dev, void *id)
580{
581 struct devres_node *node;
582
583 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
584 struct devres_group *grp;
585
586 if (node->release != &group_open_release)
587 continue;
588
589 grp = container_of(node, struct devres_group, node[0]);
590
591 if (id) {
592 if (grp->id == id)
593 return grp;
594 } else if (list_empty(&grp->node[1].entry))
595 return grp;
596 }
597
598 return NULL;
599}
600
601/**
602 * devres_close_group - Close a devres group
603 * @dev: Device to close devres group for
604 * @id: ID of target group, can be NULL
605 *
606 * Close the group identified by @id. If @id is NULL, the latest open
607 * group is selected.
608 */
609void devres_close_group(struct device *dev, void *id)
610{
611 struct devres_group *grp;
612 unsigned long flags;
613
614 spin_lock_irqsave(&dev->devres_lock, flags);
615
616 grp = find_group(dev, id);
617 if (grp)
618 add_dr(dev, &grp->node[1]);
619 else
620 WARN_ON(1);
621
622 spin_unlock_irqrestore(&dev->devres_lock, flags);
623}
624EXPORT_SYMBOL_GPL(devres_close_group);
625
626/**
627 * devres_remove_group - Remove a devres group
628 * @dev: Device to remove group for
629 * @id: ID of target group, can be NULL
630 *
631 * Remove the group identified by @id. If @id is NULL, the latest
632 * open group is selected. Note that removing a group doesn't affect
633 * any other resources.
634 */
635void devres_remove_group(struct device *dev, void *id)
636{
637 struct devres_group *grp;
638 unsigned long flags;
639
640 spin_lock_irqsave(&dev->devres_lock, flags);
641
642 grp = find_group(dev, id);
643 if (grp) {
644 list_del_init(&grp->node[0].entry);
645 list_del_init(&grp->node[1].entry);
646 devres_log(dev, &grp->node[0], "REM");
647 } else
648 WARN_ON(1);
649
650 spin_unlock_irqrestore(&dev->devres_lock, flags);
651
652 kfree(grp);
653}
654EXPORT_SYMBOL_GPL(devres_remove_group);
655
656/**
657 * devres_release_group - Release resources in a devres group
658 * @dev: Device to release group for
659 * @id: ID of target group, can be NULL
660 *
661 * Release all resources in the group identified by @id. If @id is
662 * NULL, the latest open group is selected. The selected group and
663 * groups properly nested inside the selected group are removed.
664 *
665 * RETURNS:
666 * The number of released non-group resources.
667 */
668int devres_release_group(struct device *dev, void *id)
669{
670 struct devres_group *grp;
671 unsigned long flags;
672 LIST_HEAD(todo);
673 int cnt = 0;
674
675 spin_lock_irqsave(&dev->devres_lock, flags);
676
677 grp = find_group(dev, id);
678 if (grp) {
679 struct list_head *first = &grp->node[0].entry;
680 struct list_head *end = &dev->devres_head;
681
682 if (!list_empty(&grp->node[1].entry))
683 end = grp->node[1].entry.next;
684
685 cnt = remove_nodes(dev, first, end, &todo);
686 spin_unlock_irqrestore(&dev->devres_lock, flags);
687
688 release_nodes(dev, &todo);
689 } else {
690 WARN_ON(1);
691 spin_unlock_irqrestore(&dev->devres_lock, flags);
692 }
693
694 return cnt;
695}
696EXPORT_SYMBOL_GPL(devres_release_group);
697
698/*
699 * Custom devres actions allow inserting a simple function call
700 * into the teardown sequence.
701 */
702
703struct action_devres {
704 void *data;
705 void (*action)(void *);
706};
707
708static int devm_action_match(struct device *dev, void *res, void *p)
709{
710 struct action_devres *devres = res;
711 struct action_devres *target = p;
712
713 return devres->action == target->action &&
714 devres->data == target->data;
715}
716
717static void devm_action_release(struct device *dev, void *res)
718{
719 struct action_devres *devres = res;
720
721 devres->action(devres->data);
722}
723
724/**
725 * __devm_add_action() - add a custom action to list of managed resources
726 * @dev: Device that owns the action
727 * @action: Function that should be called
728 * @data: Pointer to data passed to @action implementation
729 * @name: Name of the resource (for debugging purposes)
730 *
731 * This adds a custom action to the list of managed resources so that
732 * it gets executed as part of standard resource unwinding.
733 */
734int __devm_add_action(struct device *dev, void (*action)(void *), void *data, const char *name)
735{
736 struct action_devres *devres;
737
738 devres = __devres_alloc_node(devm_action_release, sizeof(struct action_devres),
739 GFP_KERNEL, NUMA_NO_NODE, name);
740 if (!devres)
741 return -ENOMEM;
742
743 devres->data = data;
744 devres->action = action;
745
746 devres_add(dev, devres);
747 return 0;
748}
749EXPORT_SYMBOL_GPL(__devm_add_action);
750
751/**
752 * devm_remove_action() - removes previously added custom action
753 * @dev: Device that owns the action
754 * @action: Function implementing the action
755 * @data: Pointer to data passed to @action implementation
756 *
757 * Removes instance of @action previously added by devm_add_action().
758 * Both action and data should match one of the existing entries.
759 */
760void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
761{
762 struct action_devres devres = {
763 .data = data,
764 .action = action,
765 };
766
767 WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
768 &devres));
769}
770EXPORT_SYMBOL_GPL(devm_remove_action);
771
772/**
773 * devm_release_action() - release previously added custom action
774 * @dev: Device that owns the action
775 * @action: Function implementing the action
776 * @data: Pointer to data passed to @action implementation
777 *
778 * Releases and removes instance of @action previously added by
779 * devm_add_action(). Both action and data should match one of the
780 * existing entries.
781 */
782void devm_release_action(struct device *dev, void (*action)(void *), void *data)
783{
784 struct action_devres devres = {
785 .data = data,
786 .action = action,
787 };
788
789 WARN_ON(devres_release(dev, devm_action_release, devm_action_match,
790 &devres));
791
792}
793EXPORT_SYMBOL_GPL(devm_release_action);
794
795/*
796 * Managed kmalloc/kfree
797 */
798static void devm_kmalloc_release(struct device *dev, void *res)
799{
800 /* noop */
801}
802
803static int devm_kmalloc_match(struct device *dev, void *res, void *data)
804{
805 return res == data;
806}
807
808/**
809 * devm_kmalloc - Resource-managed kmalloc
810 * @dev: Device to allocate memory for
811 * @size: Allocation size
812 * @gfp: Allocation gfp flags
813 *
814 * Managed kmalloc. Memory allocated with this function is
815 * automatically freed on driver detach. Like all other devres
816 * resources, guaranteed alignment is unsigned long long.
817 *
818 * RETURNS:
819 * Pointer to allocated memory on success, NULL on failure.
820 */
821void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
822{
823 struct devres *dr;
824
825 if (unlikely(!size))
826 return ZERO_SIZE_PTR;
827
828 /* use raw alloc_dr for kmalloc caller tracing */
829 dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
830 if (unlikely(!dr))
831 return NULL;
832
833 /*
834 * This is named devm_kzalloc_release for historical reasons
835 * The initial implementation did not support kmalloc, only kzalloc
836 */
837 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
838 devres_add(dev, dr->data);
839 return dr->data;
840}
841EXPORT_SYMBOL_GPL(devm_kmalloc);
842
843/**
844 * devm_krealloc - Resource-managed krealloc()
845 * @dev: Device to re-allocate memory for
846 * @ptr: Pointer to the memory chunk to re-allocate
847 * @new_size: New allocation size
848 * @gfp: Allocation gfp flags
849 *
850 * Managed krealloc(). Resizes the memory chunk allocated with devm_kmalloc().
851 * Behaves similarly to regular krealloc(): if @ptr is NULL or ZERO_SIZE_PTR,
852 * it's the equivalent of devm_kmalloc(). If new_size is zero, it frees the
853 * previously allocated memory and returns ZERO_SIZE_PTR. This function doesn't
854 * change the order in which the release callback for the re-alloc'ed devres
855 * will be called (except when falling back to devm_kmalloc() or when freeing
856 * resources when new_size is zero). The contents of the memory are preserved
857 * up to the lesser of new and old sizes.
858 */
859void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
860{
861 size_t total_new_size, total_old_size;
862 struct devres *old_dr, *new_dr;
863 unsigned long flags;
864
865 if (unlikely(!new_size)) {
866 devm_kfree(dev, ptr);
867 return ZERO_SIZE_PTR;
868 }
869
870 if (unlikely(ZERO_OR_NULL_PTR(ptr)))
871 return devm_kmalloc(dev, new_size, gfp);
872
873 if (WARN_ON(is_kernel_rodata((unsigned long)ptr)))
874 /*
875 * We cannot reliably realloc a const string returned by
876 * devm_kstrdup_const().
877 */
878 return NULL;
879
880 if (!check_dr_size(new_size, &total_new_size))
881 return NULL;
882
883 total_old_size = ksize(container_of(ptr, struct devres, data));
884 if (total_old_size == 0) {
885 WARN(1, "Pointer doesn't point to dynamically allocated memory.");
886 return NULL;
887 }
888
889 /*
890 * If new size is smaller or equal to the actual number of bytes
891 * allocated previously - just return the same pointer.
892 */
893 if (total_new_size <= total_old_size)
894 return ptr;
895
896 /*
897 * Otherwise: allocate new, larger chunk. We need to allocate before
898 * taking the lock as most probably the caller uses GFP_KERNEL.
899 */
900 new_dr = alloc_dr(devm_kmalloc_release,
901 total_new_size, gfp, dev_to_node(dev));
902 if (!new_dr)
903 return NULL;
904
905 /*
906 * The spinlock protects the linked list against concurrent
907 * modifications but not the resource itself.
908 */
909 spin_lock_irqsave(&dev->devres_lock, flags);
910
911 old_dr = find_dr(dev, devm_kmalloc_release, devm_kmalloc_match, ptr);
912 if (!old_dr) {
913 spin_unlock_irqrestore(&dev->devres_lock, flags);
914 kfree(new_dr);
915 WARN(1, "Memory chunk not managed or managed by a different device.");
916 return NULL;
917 }
918
919 replace_dr(dev, &old_dr->node, &new_dr->node);
920
921 spin_unlock_irqrestore(&dev->devres_lock, flags);
922
923 /*
924 * We can copy the memory contents after releasing the lock as we're
925 * no longer modifying the list links.
926 */
927 memcpy(new_dr->data, old_dr->data,
928 total_old_size - offsetof(struct devres, data));
929 /*
930 * Same for releasing the old devres - it's now been removed from the
931 * list. This is also the reason why we must not use devm_kfree() - the
932 * links are no longer valid.
933 */
934 kfree(old_dr);
935
936 return new_dr->data;
937}
938EXPORT_SYMBOL_GPL(devm_krealloc);
939
940/**
941 * devm_kstrdup - Allocate resource managed space and
942 * copy an existing string into that.
943 * @dev: Device to allocate memory for
944 * @s: the string to duplicate
945 * @gfp: the GFP mask used in the devm_kmalloc() call when
946 * allocating memory
947 * RETURNS:
948 * Pointer to allocated string on success, NULL on failure.
949 */
950char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
951{
952 size_t size;
953 char *buf;
954
955 if (!s)
956 return NULL;
957
958 size = strlen(s) + 1;
959 buf = devm_kmalloc(dev, size, gfp);
960 if (buf)
961 memcpy(buf, s, size);
962 return buf;
963}
964EXPORT_SYMBOL_GPL(devm_kstrdup);
965
966/**
967 * devm_kstrdup_const - resource managed conditional string duplication
968 * @dev: device for which to duplicate the string
969 * @s: the string to duplicate
970 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
971 *
972 * Strings allocated by devm_kstrdup_const will be automatically freed when
973 * the associated device is detached.
974 *
975 * RETURNS:
976 * Source string if it is in .rodata section otherwise it falls back to
977 * devm_kstrdup.
978 */
979const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
980{
981 if (is_kernel_rodata((unsigned long)s))
982 return s;
983
984 return devm_kstrdup(dev, s, gfp);
985}
986EXPORT_SYMBOL_GPL(devm_kstrdup_const);
987
988/**
989 * devm_kvasprintf - Allocate resource managed space and format a string
990 * into that.
991 * @dev: Device to allocate memory for
992 * @gfp: the GFP mask used in the devm_kmalloc() call when
993 * allocating memory
994 * @fmt: The printf()-style format string
995 * @ap: Arguments for the format string
996 * RETURNS:
997 * Pointer to allocated string on success, NULL on failure.
998 */
999char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
1000 va_list ap)
1001{
1002 unsigned int len;
1003 char *p;
1004 va_list aq;
1005
1006 va_copy(aq, ap);
1007 len = vsnprintf(NULL, 0, fmt, aq);
1008 va_end(aq);
1009
1010 p = devm_kmalloc(dev, len+1, gfp);
1011 if (!p)
1012 return NULL;
1013
1014 vsnprintf(p, len+1, fmt, ap);
1015
1016 return p;
1017}
1018EXPORT_SYMBOL(devm_kvasprintf);
1019
1020/**
1021 * devm_kasprintf - Allocate resource managed space and format a string
1022 * into that.
1023 * @dev: Device to allocate memory for
1024 * @gfp: the GFP mask used in the devm_kmalloc() call when
1025 * allocating memory
1026 * @fmt: The printf()-style format string
1027 * @...: Arguments for the format string
1028 * RETURNS:
1029 * Pointer to allocated string on success, NULL on failure.
1030 */
1031char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
1032{
1033 va_list ap;
1034 char *p;
1035
1036 va_start(ap, fmt);
1037 p = devm_kvasprintf(dev, gfp, fmt, ap);
1038 va_end(ap);
1039
1040 return p;
1041}
1042EXPORT_SYMBOL_GPL(devm_kasprintf);
1043
1044/**
1045 * devm_kfree - Resource-managed kfree
1046 * @dev: Device this memory belongs to
1047 * @p: Memory to free
1048 *
1049 * Free memory allocated with devm_kmalloc().
1050 */
1051void devm_kfree(struct device *dev, const void *p)
1052{
1053 int rc;
1054
1055 /*
1056 * Special cases: pointer to a string in .rodata returned by
1057 * devm_kstrdup_const() or NULL/ZERO ptr.
1058 */
1059 if (unlikely(is_kernel_rodata((unsigned long)p) || ZERO_OR_NULL_PTR(p)))
1060 return;
1061
1062 rc = devres_destroy(dev, devm_kmalloc_release,
1063 devm_kmalloc_match, (void *)p);
1064 WARN_ON(rc);
1065}
1066EXPORT_SYMBOL_GPL(devm_kfree);
1067
1068/**
1069 * devm_kmemdup - Resource-managed kmemdup
1070 * @dev: Device this memory belongs to
1071 * @src: Memory region to duplicate
1072 * @len: Memory region length
1073 * @gfp: GFP mask to use
1074 *
1075 * Duplicate region of a memory using resource managed kmalloc
1076 */
1077void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
1078{
1079 void *p;
1080
1081 p = devm_kmalloc(dev, len, gfp);
1082 if (p)
1083 memcpy(p, src, len);
1084
1085 return p;
1086}
1087EXPORT_SYMBOL_GPL(devm_kmemdup);
1088
1089struct pages_devres {
1090 unsigned long addr;
1091 unsigned int order;
1092};
1093
1094static int devm_pages_match(struct device *dev, void *res, void *p)
1095{
1096 struct pages_devres *devres = res;
1097 struct pages_devres *target = p;
1098
1099 return devres->addr == target->addr;
1100}
1101
1102static void devm_pages_release(struct device *dev, void *res)
1103{
1104 struct pages_devres *devres = res;
1105
1106 free_pages(devres->addr, devres->order);
1107}
1108
1109/**
1110 * devm_get_free_pages - Resource-managed __get_free_pages
1111 * @dev: Device to allocate memory for
1112 * @gfp_mask: Allocation gfp flags
1113 * @order: Allocation size is (1 << order) pages
1114 *
1115 * Managed get_free_pages. Memory allocated with this function is
1116 * automatically freed on driver detach.
1117 *
1118 * RETURNS:
1119 * Address of allocated memory on success, 0 on failure.
1120 */
1121
1122unsigned long devm_get_free_pages(struct device *dev,
1123 gfp_t gfp_mask, unsigned int order)
1124{
1125 struct pages_devres *devres;
1126 unsigned long addr;
1127
1128 addr = __get_free_pages(gfp_mask, order);
1129
1130 if (unlikely(!addr))
1131 return 0;
1132
1133 devres = devres_alloc(devm_pages_release,
1134 sizeof(struct pages_devres), GFP_KERNEL);
1135 if (unlikely(!devres)) {
1136 free_pages(addr, order);
1137 return 0;
1138 }
1139
1140 devres->addr = addr;
1141 devres->order = order;
1142
1143 devres_add(dev, devres);
1144 return addr;
1145}
1146EXPORT_SYMBOL_GPL(devm_get_free_pages);
1147
1148/**
1149 * devm_free_pages - Resource-managed free_pages
1150 * @dev: Device this memory belongs to
1151 * @addr: Memory to free
1152 *
1153 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
1154 * there is no need to supply the @order.
1155 */
1156void devm_free_pages(struct device *dev, unsigned long addr)
1157{
1158 struct pages_devres devres = { .addr = addr };
1159
1160 WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
1161 &devres));
1162}
1163EXPORT_SYMBOL_GPL(devm_free_pages);
1164
1165static void devm_percpu_release(struct device *dev, void *pdata)
1166{
1167 void __percpu *p;
1168
1169 p = *(void __percpu **)pdata;
1170 free_percpu(p);
1171}
1172
1173static int devm_percpu_match(struct device *dev, void *data, void *p)
1174{
1175 struct devres *devr = container_of(data, struct devres, data);
1176
1177 return *(void **)devr->data == p;
1178}
1179
1180/**
1181 * __devm_alloc_percpu - Resource-managed alloc_percpu
1182 * @dev: Device to allocate per-cpu memory for
1183 * @size: Size of per-cpu memory to allocate
1184 * @align: Alignment of per-cpu memory to allocate
1185 *
1186 * Managed alloc_percpu. Per-cpu memory allocated with this function is
1187 * automatically freed on driver detach.
1188 *
1189 * RETURNS:
1190 * Pointer to allocated memory on success, NULL on failure.
1191 */
1192void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1193 size_t align)
1194{
1195 void *p;
1196 void __percpu *pcpu;
1197
1198 pcpu = __alloc_percpu(size, align);
1199 if (!pcpu)
1200 return NULL;
1201
1202 p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1203 if (!p) {
1204 free_percpu(pcpu);
1205 return NULL;
1206 }
1207
1208 *(void __percpu **)p = pcpu;
1209
1210 devres_add(dev, p);
1211
1212 return pcpu;
1213}
1214EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1215
1216/**
1217 * devm_free_percpu - Resource-managed free_percpu
1218 * @dev: Device this memory belongs to
1219 * @pdata: Per-cpu memory to free
1220 *
1221 * Free memory allocated with devm_alloc_percpu().
1222 */
1223void devm_free_percpu(struct device *dev, void __percpu *pdata)
1224{
1225 WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
1226 (__force void *)pdata));
1227}
1228EXPORT_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);