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, name: node->name, size: 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(size: *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: &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(list: &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, op: "ADD");
135 BUG_ON(!list_empty(&node->entry));
136 list_add_tail(new: &node->entry, head: &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, node: old, op: "REPLACE");
143 BUG_ON(!list_empty(&new->entry));
144 list_replace(old: &old->entry, new: &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 | __GFP_ZERO, nid);
168 if (unlikely(!dr))
169 return NULL;
170 set_node_dbginfo(node: &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(lock: &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(objp: 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, node: &dr->node);
250 spin_unlock_irqrestore(lock: &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(lock: &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, release: new_dr->node.release, match, match_data);
325 if (!dr) {
326 add_dr(dev, node: &new_dr->node);
327 dr = new_dr;
328 new_res = NULL;
329 }
330 spin_unlock_irqrestore(lock: &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(entry: &dr->node.entry);
362 devres_log(dev, node: &dr->node, op: "REM");
363 }
364 spin_unlock_irqrestore(lock: &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(list: &node->entry, head: 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(head: &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(list: &grp->node[0].entry, head: todo);
489 list_del_init(entry: &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, node: &dr->node, op: "REL");
505 dr->node.release(dev, dr->data);
506 kfree(objp: 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(head: &dev->devres_head))
529 return 0;
530
531 spin_lock_irqsave(&dev->devres_lock, flags);
532 cnt = remove_nodes(dev, first: dev->devres_head.next, end: &dev->devres_head, todo: &todo);
533 spin_unlock_irqrestore(lock: &dev->devres_lock, flags);
534
535 release_nodes(dev, todo: &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(list: &grp->node[0].entry);
564 INIT_LIST_HEAD(list: &grp->node[1].entry);
565 set_node_dbginfo(node: &grp->node[0], name: "grp<", size: 0);
566 set_node_dbginfo(node: &grp->node[1], name: "grp>", size: 0);
567 grp->id = grp;
568 if (id)
569 grp->id = id;
570 grp->color = 0;
571
572 spin_lock_irqsave(&dev->devres_lock, flags);
573 add_dr(dev, node: &grp->node[0]);
574 spin_unlock_irqrestore(lock: &dev->devres_lock, flags);
575 return grp->id;
576}
577EXPORT_SYMBOL_GPL(devres_open_group);
578
579/*
580 * Find devres group with ID @id. If @id is NULL, look for the latest open
581 * group.
582 */
583static struct devres_group *find_group(struct device *dev, void *id)
584{
585 struct devres_node *node;
586
587 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
588 struct devres_group *grp;
589
590 if (node->release != &group_open_release)
591 continue;
592
593 grp = container_of(node, struct devres_group, node[0]);
594
595 if (id) {
596 if (grp->id == id)
597 return grp;
598 } else if (list_empty(head: &grp->node[1].entry))
599 return grp;
600 }
601
602 return NULL;
603}
604
605/**
606 * devres_close_group - Close a devres group
607 * @dev: Device to close devres group for
608 * @id: ID of target group, can be NULL
609 *
610 * Close the group identified by @id. If @id is NULL, the latest open
611 * group is selected.
612 */
613void devres_close_group(struct device *dev, void *id)
614{
615 struct devres_group *grp;
616 unsigned long flags;
617
618 spin_lock_irqsave(&dev->devres_lock, flags);
619
620 grp = find_group(dev, id);
621 if (grp)
622 add_dr(dev, node: &grp->node[1]);
623 else
624 WARN_ON(1);
625
626 spin_unlock_irqrestore(lock: &dev->devres_lock, flags);
627}
628EXPORT_SYMBOL_GPL(devres_close_group);
629
630/**
631 * devres_remove_group - Remove a devres group
632 * @dev: Device to remove group for
633 * @id: ID of target group, can be NULL
634 *
635 * Remove the group identified by @id. If @id is NULL, the latest
636 * open group is selected. Note that removing a group doesn't affect
637 * any other resources.
638 */
639void devres_remove_group(struct device *dev, void *id)
640{
641 struct devres_group *grp;
642 unsigned long flags;
643
644 spin_lock_irqsave(&dev->devres_lock, flags);
645
646 grp = find_group(dev, id);
647 if (grp) {
648 list_del_init(entry: &grp->node[0].entry);
649 list_del_init(entry: &grp->node[1].entry);
650 devres_log(dev, node: &grp->node[0], op: "REM");
651 } else
652 WARN_ON(1);
653
654 spin_unlock_irqrestore(lock: &dev->devres_lock, flags);
655
656 kfree(objp: grp);
657}
658EXPORT_SYMBOL_GPL(devres_remove_group);
659
660/**
661 * devres_release_group - Release resources in a devres group
662 * @dev: Device to release group for
663 * @id: ID of target group, can be NULL
664 *
665 * Release all resources in the group identified by @id. If @id is
666 * NULL, the latest open group is selected. The selected group and
667 * groups properly nested inside the selected group are removed.
668 *
669 * RETURNS:
670 * The number of released non-group resources.
671 */
672int devres_release_group(struct device *dev, void *id)
673{
674 struct devres_group *grp;
675 unsigned long flags;
676 LIST_HEAD(todo);
677 int cnt = 0;
678
679 spin_lock_irqsave(&dev->devres_lock, flags);
680
681 grp = find_group(dev, id);
682 if (grp) {
683 struct list_head *first = &grp->node[0].entry;
684 struct list_head *end = &dev->devres_head;
685
686 if (!list_empty(head: &grp->node[1].entry))
687 end = grp->node[1].entry.next;
688
689 cnt = remove_nodes(dev, first, end, todo: &todo);
690 spin_unlock_irqrestore(lock: &dev->devres_lock, flags);
691
692 release_nodes(dev, todo: &todo);
693 } else if (list_empty(head: &dev->devres_head)) {
694 /*
695 * dev is probably dying via devres_release_all(): groups
696 * have already been removed and are on the process of
697 * being released - don't touch and don't warn.
698 */
699 spin_unlock_irqrestore(lock: &dev->devres_lock, flags);
700 } else {
701 WARN_ON(1);
702 spin_unlock_irqrestore(lock: &dev->devres_lock, flags);
703 }
704
705 return cnt;
706}
707EXPORT_SYMBOL_GPL(devres_release_group);
708
709/*
710 * Custom devres actions allow inserting a simple function call
711 * into the teardown sequence.
712 */
713
714struct action_devres {
715 void *data;
716 void (*action)(void *);
717};
718
719static int devm_action_match(struct device *dev, void *res, void *p)
720{
721 struct action_devres *devres = res;
722 struct action_devres *target = p;
723
724 return devres->action == target->action &&
725 devres->data == target->data;
726}
727
728static void devm_action_release(struct device *dev, void *res)
729{
730 struct action_devres *devres = res;
731
732 devres->action(devres->data);
733}
734
735/**
736 * __devm_add_action() - add a custom action to list of managed resources
737 * @dev: Device that owns the action
738 * @action: Function that should be called
739 * @data: Pointer to data passed to @action implementation
740 * @name: Name of the resource (for debugging purposes)
741 *
742 * This adds a custom action to the list of managed resources so that
743 * it gets executed as part of standard resource unwinding.
744 */
745int __devm_add_action(struct device *dev, void (*action)(void *), void *data, const char *name)
746{
747 struct action_devres *devres;
748
749 devres = __devres_alloc_node(devm_action_release, sizeof(struct action_devres),
750 GFP_KERNEL, NUMA_NO_NODE, name);
751 if (!devres)
752 return -ENOMEM;
753
754 devres->data = data;
755 devres->action = action;
756
757 devres_add(dev, devres);
758 return 0;
759}
760EXPORT_SYMBOL_GPL(__devm_add_action);
761
762bool devm_is_action_added(struct device *dev, void (*action)(void *), void *data)
763{
764 struct action_devres devres = {
765 .data = data,
766 .action = action,
767 };
768
769 return devres_find(dev, devm_action_release, devm_action_match, &devres);
770}
771EXPORT_SYMBOL_GPL(devm_is_action_added);
772
773/**
774 * devm_remove_action_nowarn() - removes previously added custom action
775 * @dev: Device that owns the action
776 * @action: Function implementing the action
777 * @data: Pointer to data passed to @action implementation
778 *
779 * Removes instance of @action previously added by devm_add_action().
780 * Both action and data should match one of the existing entries.
781 *
782 * In contrast to devm_remove_action(), this function does not WARN() if no
783 * entry could have been found.
784 *
785 * This should only be used if the action is contained in an object with
786 * independent lifetime management, e.g. the Devres rust abstraction.
787 *
788 * Causing the warning from regular driver code most likely indicates an abuse
789 * of the devres API.
790 *
791 * Returns: 0 on success, -ENOENT if no entry could have been found.
792 */
793int devm_remove_action_nowarn(struct device *dev,
794 void (*action)(void *),
795 void *data)
796{
797 struct action_devres devres = {
798 .data = data,
799 .action = action,
800 };
801
802 return devres_destroy(dev, devm_action_release, devm_action_match,
803 &devres);
804}
805EXPORT_SYMBOL_GPL(devm_remove_action_nowarn);
806
807/**
808 * devm_release_action() - release previously added custom action
809 * @dev: Device that owns the action
810 * @action: Function implementing the action
811 * @data: Pointer to data passed to @action implementation
812 *
813 * Releases and removes instance of @action previously added by
814 * devm_add_action(). Both action and data should match one of the
815 * existing entries.
816 */
817void devm_release_action(struct device *dev, void (*action)(void *), void *data)
818{
819 struct action_devres devres = {
820 .data = data,
821 .action = action,
822 };
823
824 WARN_ON(devres_release(dev, devm_action_release, devm_action_match,
825 &devres));
826
827}
828EXPORT_SYMBOL_GPL(devm_release_action);
829
830/*
831 * Managed kmalloc/kfree
832 */
833static void devm_kmalloc_release(struct device *dev, void *res)
834{
835 /* noop */
836}
837
838static int devm_kmalloc_match(struct device *dev, void *res, void *data)
839{
840 return res == data;
841}
842
843/**
844 * devm_kmalloc - Resource-managed kmalloc
845 * @dev: Device to allocate memory for
846 * @size: Allocation size
847 * @gfp: Allocation gfp flags
848 *
849 * Managed kmalloc. Memory allocated with this function is
850 * automatically freed on driver detach. Like all other devres
851 * resources, guaranteed alignment is unsigned long long.
852 *
853 * RETURNS:
854 * Pointer to allocated memory on success, NULL on failure.
855 */
856void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
857{
858 struct devres *dr;
859
860 if (unlikely(!size))
861 return ZERO_SIZE_PTR;
862
863 /* use raw alloc_dr for kmalloc caller tracing */
864 dr = alloc_dr(release: devm_kmalloc_release, size, gfp, nid: dev_to_node(dev));
865 if (unlikely(!dr))
866 return NULL;
867
868 /*
869 * This is named devm_kzalloc_release for historical reasons
870 * The initial implementation did not support kmalloc, only kzalloc
871 */
872 set_node_dbginfo(node: &dr->node, name: "devm_kzalloc_release", size);
873 devres_add(dev, dr->data);
874 return dr->data;
875}
876EXPORT_SYMBOL_GPL(devm_kmalloc);
877
878/**
879 * devm_krealloc - Resource-managed krealloc()
880 * @dev: Device to re-allocate memory for
881 * @ptr: Pointer to the memory chunk to re-allocate
882 * @new_size: New allocation size
883 * @gfp: Allocation gfp flags
884 *
885 * Managed krealloc(). Resizes the memory chunk allocated with devm_kmalloc().
886 * Behaves similarly to regular krealloc(): if @ptr is NULL or ZERO_SIZE_PTR,
887 * it's the equivalent of devm_kmalloc(). If new_size is zero, it frees the
888 * previously allocated memory and returns ZERO_SIZE_PTR. This function doesn't
889 * change the order in which the release callback for the re-alloc'ed devres
890 * will be called (except when falling back to devm_kmalloc() or when freeing
891 * resources when new_size is zero). The contents of the memory are preserved
892 * up to the lesser of new and old sizes.
893 */
894void *devm_krealloc(struct device *dev, void *ptr, size_t new_size, gfp_t gfp)
895{
896 size_t total_new_size, total_old_size;
897 struct devres *old_dr, *new_dr;
898 unsigned long flags;
899
900 if (unlikely(!new_size)) {
901 devm_kfree(dev, p: ptr);
902 return ZERO_SIZE_PTR;
903 }
904
905 if (unlikely(ZERO_OR_NULL_PTR(ptr)))
906 return devm_kmalloc(dev, new_size, gfp);
907
908 if (WARN_ON(is_kernel_rodata((unsigned long)ptr)))
909 /*
910 * We cannot reliably realloc a const string returned by
911 * devm_kstrdup_const().
912 */
913 return NULL;
914
915 if (!check_dr_size(size: new_size, tot_size: &total_new_size))
916 return NULL;
917
918 total_old_size = ksize(container_of(ptr, struct devres, data));
919 if (total_old_size == 0) {
920 WARN(1, "Pointer doesn't point to dynamically allocated memory.");
921 return NULL;
922 }
923
924 /*
925 * If new size is smaller or equal to the actual number of bytes
926 * allocated previously - just return the same pointer.
927 */
928 if (total_new_size <= total_old_size)
929 return ptr;
930
931 /*
932 * Otherwise: allocate new, larger chunk. We need to allocate before
933 * taking the lock as most probably the caller uses GFP_KERNEL.
934 * alloc_dr() will call check_dr_size() to reserve extra memory
935 * for struct devres automatically, so size @new_size user request
936 * is delivered to it directly as devm_kmalloc() does.
937 */
938 new_dr = alloc_dr(release: devm_kmalloc_release,
939 size: new_size, gfp, nid: dev_to_node(dev));
940 if (!new_dr)
941 return NULL;
942
943 /*
944 * The spinlock protects the linked list against concurrent
945 * modifications but not the resource itself.
946 */
947 spin_lock_irqsave(&dev->devres_lock, flags);
948
949 old_dr = find_dr(dev, release: devm_kmalloc_release, match: devm_kmalloc_match, match_data: ptr);
950 if (!old_dr) {
951 spin_unlock_irqrestore(lock: &dev->devres_lock, flags);
952 kfree(objp: new_dr);
953 WARN(1, "Memory chunk not managed or managed by a different device.");
954 return NULL;
955 }
956
957 replace_dr(dev, old: &old_dr->node, new: &new_dr->node);
958
959 spin_unlock_irqrestore(lock: &dev->devres_lock, flags);
960
961 /*
962 * We can copy the memory contents after releasing the lock as we're
963 * no longer modifying the list links.
964 */
965 memcpy(new_dr->data, old_dr->data,
966 total_old_size - offsetof(struct devres, data));
967 /*
968 * Same for releasing the old devres - it's now been removed from the
969 * list. This is also the reason why we must not use devm_kfree() - the
970 * links are no longer valid.
971 */
972 kfree(objp: old_dr);
973
974 return new_dr->data;
975}
976EXPORT_SYMBOL_GPL(devm_krealloc);
977
978/**
979 * devm_kstrdup - Allocate resource managed space and
980 * copy an existing string into that.
981 * @dev: Device to allocate memory for
982 * @s: the string to duplicate
983 * @gfp: the GFP mask used in the devm_kmalloc() call when
984 * allocating memory
985 * RETURNS:
986 * Pointer to allocated string on success, NULL on failure.
987 */
988char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
989{
990 if (!s)
991 return NULL;
992
993 return devm_kmemdup(dev, src: s, strlen(s) + 1, gfp);
994}
995EXPORT_SYMBOL_GPL(devm_kstrdup);
996
997/**
998 * devm_kstrdup_const - resource managed conditional string duplication
999 * @dev: device for which to duplicate the string
1000 * @s: the string to duplicate
1001 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
1002 *
1003 * Strings allocated by devm_kstrdup_const will be automatically freed when
1004 * the associated device is detached.
1005 *
1006 * RETURNS:
1007 * Source string if it is in .rodata section otherwise it falls back to
1008 * devm_kstrdup.
1009 */
1010const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
1011{
1012 if (is_kernel_rodata(addr: (unsigned long)s))
1013 return s;
1014
1015 return devm_kstrdup(dev, s, gfp);
1016}
1017EXPORT_SYMBOL_GPL(devm_kstrdup_const);
1018
1019/**
1020 * devm_kvasprintf - Allocate resource managed space and format a string
1021 * into that.
1022 * @dev: Device to allocate memory for
1023 * @gfp: the GFP mask used in the devm_kmalloc() call when
1024 * allocating memory
1025 * @fmt: The printf()-style format string
1026 * @ap: Arguments for the format string
1027 * RETURNS:
1028 * Pointer to allocated string on success, NULL on failure.
1029 */
1030char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
1031 va_list ap)
1032{
1033 unsigned int len;
1034 char *p;
1035 va_list aq;
1036
1037 va_copy(aq, ap);
1038 len = vsnprintf(NULL, size: 0, fmt, args: aq);
1039 va_end(aq);
1040
1041 p = devm_kmalloc(dev, len+1, gfp);
1042 if (!p)
1043 return NULL;
1044
1045 vsnprintf(buf: p, size: len+1, fmt, args: ap);
1046
1047 return p;
1048}
1049EXPORT_SYMBOL(devm_kvasprintf);
1050
1051/**
1052 * devm_kasprintf - Allocate resource managed space and format a string
1053 * into that.
1054 * @dev: Device to allocate memory for
1055 * @gfp: the GFP mask used in the devm_kmalloc() call when
1056 * allocating memory
1057 * @fmt: The printf()-style format string
1058 * @...: Arguments for the format string
1059 * RETURNS:
1060 * Pointer to allocated string on success, NULL on failure.
1061 */
1062char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
1063{
1064 va_list ap;
1065 char *p;
1066
1067 va_start(ap, fmt);
1068 p = devm_kvasprintf(dev, gfp, fmt, ap);
1069 va_end(ap);
1070
1071 return p;
1072}
1073EXPORT_SYMBOL_GPL(devm_kasprintf);
1074
1075/**
1076 * devm_kfree - Resource-managed kfree
1077 * @dev: Device this memory belongs to
1078 * @p: Memory to free
1079 *
1080 * Free memory allocated with devm_kmalloc().
1081 */
1082void devm_kfree(struct device *dev, const void *p)
1083{
1084 int rc;
1085
1086 /*
1087 * Special cases: pointer to a string in .rodata returned by
1088 * devm_kstrdup_const() or NULL/ZERO ptr.
1089 */
1090 if (unlikely(is_kernel_rodata((unsigned long)p) || ZERO_OR_NULL_PTR(p)))
1091 return;
1092
1093 rc = devres_destroy(dev, devm_kmalloc_release,
1094 devm_kmalloc_match, (void *)p);
1095 WARN_ON(rc);
1096}
1097EXPORT_SYMBOL_GPL(devm_kfree);
1098
1099/**
1100 * devm_kmemdup - Resource-managed kmemdup
1101 * @dev: Device this memory belongs to
1102 * @src: Memory region to duplicate
1103 * @len: Memory region length
1104 * @gfp: GFP mask to use
1105 *
1106 * Duplicate region of a memory using resource managed kmalloc
1107 */
1108void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
1109{
1110 void *p;
1111
1112 p = devm_kmalloc(dev, len, gfp);
1113 if (p)
1114 memcpy(p, src, len);
1115
1116 return p;
1117}
1118EXPORT_SYMBOL_GPL(devm_kmemdup);
1119
1120/**
1121 * devm_kmemdup_const - conditionally duplicate and manage a region of memory
1122 *
1123 * @dev: Device this memory belongs to
1124 * @src: memory region to duplicate
1125 * @len: memory region length,
1126 * @gfp: GFP mask to use
1127 *
1128 * Return: source address if it is in .rodata or the return value of kmemdup()
1129 * to which the function falls back otherwise.
1130 */
1131const void *
1132devm_kmemdup_const(struct device *dev, const void *src, size_t len, gfp_t gfp)
1133{
1134 if (is_kernel_rodata(addr: (unsigned long)src))
1135 return src;
1136
1137 return devm_kmemdup(dev, src, len, gfp);
1138}
1139EXPORT_SYMBOL_GPL(devm_kmemdup_const);
1140
1141struct pages_devres {
1142 unsigned long addr;
1143 unsigned int order;
1144};
1145
1146static int devm_pages_match(struct device *dev, void *res, void *p)
1147{
1148 struct pages_devres *devres = res;
1149 struct pages_devres *target = p;
1150
1151 return devres->addr == target->addr;
1152}
1153
1154static void devm_pages_release(struct device *dev, void *res)
1155{
1156 struct pages_devres *devres = res;
1157
1158 free_pages(addr: devres->addr, order: devres->order);
1159}
1160
1161/**
1162 * devm_get_free_pages - Resource-managed __get_free_pages
1163 * @dev: Device to allocate memory for
1164 * @gfp_mask: Allocation gfp flags
1165 * @order: Allocation size is (1 << order) pages
1166 *
1167 * Managed get_free_pages. Memory allocated with this function is
1168 * automatically freed on driver detach.
1169 *
1170 * RETURNS:
1171 * Address of allocated memory on success, 0 on failure.
1172 */
1173
1174unsigned long devm_get_free_pages(struct device *dev,
1175 gfp_t gfp_mask, unsigned int order)
1176{
1177 struct pages_devres *devres;
1178 unsigned long addr;
1179
1180 addr = __get_free_pages(gfp_mask, order);
1181
1182 if (unlikely(!addr))
1183 return 0;
1184
1185 devres = devres_alloc(devm_pages_release,
1186 sizeof(struct pages_devres), GFP_KERNEL);
1187 if (unlikely(!devres)) {
1188 free_pages(addr, order);
1189 return 0;
1190 }
1191
1192 devres->addr = addr;
1193 devres->order = order;
1194
1195 devres_add(dev, devres);
1196 return addr;
1197}
1198EXPORT_SYMBOL_GPL(devm_get_free_pages);
1199
1200/**
1201 * devm_free_pages - Resource-managed free_pages
1202 * @dev: Device this memory belongs to
1203 * @addr: Memory to free
1204 *
1205 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
1206 * there is no need to supply the @order.
1207 */
1208void devm_free_pages(struct device *dev, unsigned long addr)
1209{
1210 struct pages_devres devres = { .addr = addr };
1211
1212 WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
1213 &devres));
1214}
1215EXPORT_SYMBOL_GPL(devm_free_pages);
1216
1217static void devm_percpu_release(struct device *dev, void *pdata)
1218{
1219 void __percpu *p;
1220
1221 p = *(void __percpu **)pdata;
1222 free_percpu(pdata: p);
1223}
1224
1225/**
1226 * __devm_alloc_percpu - Resource-managed alloc_percpu
1227 * @dev: Device to allocate per-cpu memory for
1228 * @size: Size of per-cpu memory to allocate
1229 * @align: Alignment of per-cpu memory to allocate
1230 *
1231 * Managed alloc_percpu. Per-cpu memory allocated with this function is
1232 * automatically freed on driver detach.
1233 *
1234 * RETURNS:
1235 * Pointer to allocated memory on success, NULL on failure.
1236 */
1237void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1238 size_t align)
1239{
1240 void *p;
1241 void __percpu *pcpu;
1242
1243 pcpu = __alloc_percpu(size, align);
1244 if (!pcpu)
1245 return NULL;
1246
1247 p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1248 if (!p) {
1249 free_percpu(pdata: pcpu);
1250 return NULL;
1251 }
1252
1253 *(void __percpu **)p = pcpu;
1254
1255 devres_add(dev, p);
1256
1257 return pcpu;
1258}
1259EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1260

source code of linux/drivers/base/devres.c