Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/base/devres.c - device resource management
4 *
5 * Copyright (c) 2006 SUSE Linux Products GmbH
6 * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
7 */
8
9#include <linux/device.h>
10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/percpu.h>
13
14#include <asm/sections.h>
15
16#include "base.h"
17#include "trace.h"
18
19struct devres_node {
20 struct list_head entry;
21 dr_release_t release;
22 const char *name;
23 size_t size;
24};
25
26struct devres {
27 struct devres_node node;
28 /*
29 * Some archs want to perform DMA into kmalloc caches
30 * and need a guaranteed alignment larger than
31 * the alignment of a 64-bit integer.
32 * Thus we use ARCH_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/*
2 * drivers/base/devres.c - device resource management
3 *
4 * Copyright (c) 2006 SUSE Linux Products GmbH
5 * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
6 *
7 * This file is released under the GPLv2.
8 */
9
10#include <linux/device.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/percpu.h>
14
15#include "base.h"
16
17struct devres_node {
18 struct list_head entry;
19 dr_release_t release;
20#ifdef CONFIG_DEBUG_DEVRES
21 const char *name;
22 size_t size;
23#endif
24};
25
26struct devres {
27 struct devres_node node;
28 /* -- 3 pointers */
29 unsigned long long data[]; /* guarantee ull alignment */
30};
31
32struct devres_group {
33 struct devres_node node[2];
34 void *id;
35 int color;
36 /* -- 8 pointers */
37};
38
39#ifdef CONFIG_DEBUG_DEVRES
40static int log_devres = 0;
41module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
42
43static void set_node_dbginfo(struct devres_node *node, const char *name,
44 size_t size)
45{
46 node->name = name;
47 node->size = size;
48}
49
50static void devres_log(struct device *dev, struct devres_node *node,
51 const char *op)
52{
53 if (unlikely(log_devres))
54 dev_err(dev, "DEVRES %3s %p %s (%lu bytes)\n",
55 op, node, node->name, (unsigned long)node->size);
56}
57#else /* CONFIG_DEBUG_DEVRES */
58#define set_node_dbginfo(node, n, s) do {} while (0)
59#define devres_log(dev, node, op) do {} while (0)
60#endif /* CONFIG_DEBUG_DEVRES */
61
62/*
63 * Release functions for devres group. These callbacks are used only
64 * for identification.
65 */
66static void group_open_release(struct device *dev, void *res)
67{
68 /* noop */
69}
70
71static void group_close_release(struct device *dev, void *res)
72{
73 /* noop */
74}
75
76static struct devres_group * node_to_group(struct devres_node *node)
77{
78 if (node->release == &group_open_release)
79 return container_of(node, struct devres_group, node[0]);
80 if (node->release == &group_close_release)
81 return container_of(node, struct devres_group, node[1]);
82 return NULL;
83}
84
85static __always_inline struct devres * alloc_dr(dr_release_t release,
86 size_t size, gfp_t gfp, int nid)
87{
88 size_t tot_size = sizeof(struct devres) + size;
89 struct devres *dr;
90
91 dr = kmalloc_node_track_caller(tot_size, gfp, nid);
92 if (unlikely(!dr))
93 return NULL;
94
95 memset(dr, 0, offsetof(struct devres, data));
96
97 INIT_LIST_HEAD(&dr->node.entry);
98 dr->node.release = release;
99 return dr;
100}
101
102static void add_dr(struct device *dev, struct devres_node *node)
103{
104 devres_log(dev, node, "ADD");
105 BUG_ON(!list_empty(&node->entry));
106 list_add_tail(&node->entry, &dev->devres_head);
107}
108
109#ifdef CONFIG_DEBUG_DEVRES
110void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
111 const char *name)
112{
113 struct devres *dr;
114
115 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
116 if (unlikely(!dr))
117 return NULL;
118 set_node_dbginfo(&dr->node, name, size);
119 return dr->data;
120}
121EXPORT_SYMBOL_GPL(__devres_alloc_node);
122#else
123/**
124 * devres_alloc - Allocate device resource data
125 * @release: Release function devres will be associated with
126 * @size: Allocation size
127 * @gfp: Allocation flags
128 * @nid: NUMA node
129 *
130 * Allocate devres of @size bytes. The allocated area is zeroed, then
131 * associated with @release. The returned pointer can be passed to
132 * other devres_*() functions.
133 *
134 * RETURNS:
135 * Pointer to allocated devres on success, NULL on failure.
136 */
137void * devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid)
138{
139 struct devres *dr;
140
141 dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
142 if (unlikely(!dr))
143 return NULL;
144 return dr->data;
145}
146EXPORT_SYMBOL_GPL(devres_alloc_node);
147#endif
148
149/**
150 * devres_for_each_res - Resource iterator
151 * @dev: Device to iterate resource from
152 * @release: Look for resources associated with this release function
153 * @match: Match function (optional)
154 * @match_data: Data for the match function
155 * @fn: Function to be called for each matched resource.
156 * @data: Data for @fn, the 3rd parameter of @fn
157 *
158 * Call @fn for each devres of @dev which is associated with @release
159 * and for which @match returns 1.
160 *
161 * RETURNS:
162 * void
163 */
164void devres_for_each_res(struct device *dev, dr_release_t release,
165 dr_match_t match, void *match_data,
166 void (*fn)(struct device *, void *, void *),
167 void *data)
168{
169 struct devres_node *node;
170 struct devres_node *tmp;
171 unsigned long flags;
172
173 if (!fn)
174 return;
175
176 spin_lock_irqsave(&dev->devres_lock, flags);
177 list_for_each_entry_safe_reverse(node, tmp,
178 &dev->devres_head, entry) {
179 struct devres *dr = container_of(node, struct devres, node);
180
181 if (node->release != release)
182 continue;
183 if (match && !match(dev, dr->data, match_data))
184 continue;
185 fn(dev, dr->data, data);
186 }
187 spin_unlock_irqrestore(&dev->devres_lock, flags);
188}
189EXPORT_SYMBOL_GPL(devres_for_each_res);
190
191/**
192 * devres_free - Free device resource data
193 * @res: Pointer to devres data to free
194 *
195 * Free devres created with devres_alloc().
196 */
197void devres_free(void *res)
198{
199 if (res) {
200 struct devres *dr = container_of(res, struct devres, data);
201
202 BUG_ON(!list_empty(&dr->node.entry));
203 kfree(dr);
204 }
205}
206EXPORT_SYMBOL_GPL(devres_free);
207
208/**
209 * devres_add - Register device resource
210 * @dev: Device to add resource to
211 * @res: Resource to register
212 *
213 * Register devres @res to @dev. @res should have been allocated
214 * using devres_alloc(). On driver detach, the associated release
215 * function will be invoked and devres will be freed automatically.
216 */
217void devres_add(struct device *dev, void *res)
218{
219 struct devres *dr = container_of(res, struct devres, data);
220 unsigned long flags;
221
222 spin_lock_irqsave(&dev->devres_lock, flags);
223 add_dr(dev, &dr->node);
224 spin_unlock_irqrestore(&dev->devres_lock, flags);
225}
226EXPORT_SYMBOL_GPL(devres_add);
227
228static struct devres *find_dr(struct device *dev, dr_release_t release,
229 dr_match_t match, void *match_data)
230{
231 struct devres_node *node;
232
233 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
234 struct devres *dr = container_of(node, struct devres, node);
235
236 if (node->release != release)
237 continue;
238 if (match && !match(dev, dr->data, match_data))
239 continue;
240 return dr;
241 }
242
243 return NULL;
244}
245
246/**
247 * devres_find - Find device resource
248 * @dev: Device to lookup resource from
249 * @release: Look for resources associated with this release function
250 * @match: Match function (optional)
251 * @match_data: Data for the match function
252 *
253 * Find the latest devres of @dev which is associated with @release
254 * and for which @match returns 1. If @match is NULL, it's considered
255 * to match all.
256 *
257 * RETURNS:
258 * Pointer to found devres, NULL if not found.
259 */
260void * devres_find(struct device *dev, dr_release_t release,
261 dr_match_t match, void *match_data)
262{
263 struct devres *dr;
264 unsigned long flags;
265
266 spin_lock_irqsave(&dev->devres_lock, flags);
267 dr = find_dr(dev, release, match, match_data);
268 spin_unlock_irqrestore(&dev->devres_lock, flags);
269
270 if (dr)
271 return dr->data;
272 return NULL;
273}
274EXPORT_SYMBOL_GPL(devres_find);
275
276/**
277 * devres_get - Find devres, if non-existent, add one atomically
278 * @dev: Device to lookup or add devres for
279 * @new_res: Pointer to new initialized devres to add if not found
280 * @match: Match function (optional)
281 * @match_data: Data for the match function
282 *
283 * Find the latest devres of @dev which has the same release function
284 * as @new_res and for which @match return 1. If found, @new_res is
285 * freed; otherwise, @new_res is added atomically.
286 *
287 * RETURNS:
288 * Pointer to found or added devres.
289 */
290void * devres_get(struct device *dev, void *new_res,
291 dr_match_t match, void *match_data)
292{
293 struct devres *new_dr = container_of(new_res, struct devres, data);
294 struct devres *dr;
295 unsigned long flags;
296
297 spin_lock_irqsave(&dev->devres_lock, flags);
298 dr = find_dr(dev, new_dr->node.release, match, match_data);
299 if (!dr) {
300 add_dr(dev, &new_dr->node);
301 dr = new_dr;
302 new_res = NULL;
303 }
304 spin_unlock_irqrestore(&dev->devres_lock, flags);
305 devres_free(new_res);
306
307 return dr->data;
308}
309EXPORT_SYMBOL_GPL(devres_get);
310
311/**
312 * devres_remove - Find a device resource and remove it
313 * @dev: Device to find resource from
314 * @release: Look for resources associated with this release function
315 * @match: Match function (optional)
316 * @match_data: Data for the match function
317 *
318 * Find the latest devres of @dev associated with @release and for
319 * which @match returns 1. If @match is NULL, it's considered to
320 * match all. If found, the resource is removed atomically and
321 * returned.
322 *
323 * RETURNS:
324 * Pointer to removed devres on success, NULL if not found.
325 */
326void * devres_remove(struct device *dev, dr_release_t release,
327 dr_match_t match, void *match_data)
328{
329 struct devres *dr;
330 unsigned long flags;
331
332 spin_lock_irqsave(&dev->devres_lock, flags);
333 dr = find_dr(dev, release, match, match_data);
334 if (dr) {
335 list_del_init(&dr->node.entry);
336 devres_log(dev, &dr->node, "REM");
337 }
338 spin_unlock_irqrestore(&dev->devres_lock, flags);
339
340 if (dr)
341 return dr->data;
342 return NULL;
343}
344EXPORT_SYMBOL_GPL(devres_remove);
345
346/**
347 * devres_destroy - Find a device resource and destroy it
348 * @dev: Device to find resource from
349 * @release: Look for resources associated with this release function
350 * @match: Match function (optional)
351 * @match_data: Data for the match function
352 *
353 * Find the latest devres of @dev associated with @release and for
354 * which @match returns 1. If @match is NULL, it's considered to
355 * match all. If found, the resource is removed atomically and freed.
356 *
357 * Note that the release function for the resource will not be called,
358 * only the devres-allocated data will be freed. The caller becomes
359 * responsible for freeing any other data.
360 *
361 * RETURNS:
362 * 0 if devres is found and freed, -ENOENT if not found.
363 */
364int devres_destroy(struct device *dev, dr_release_t release,
365 dr_match_t match, void *match_data)
366{
367 void *res;
368
369 res = devres_remove(dev, release, match, match_data);
370 if (unlikely(!res))
371 return -ENOENT;
372
373 devres_free(res);
374 return 0;
375}
376EXPORT_SYMBOL_GPL(devres_destroy);
377
378
379/**
380 * devres_release - Find a device resource and destroy it, calling release
381 * @dev: Device to find resource from
382 * @release: Look for resources associated with this release function
383 * @match: Match function (optional)
384 * @match_data: Data for the match function
385 *
386 * Find the latest devres of @dev associated with @release and for
387 * which @match returns 1. If @match is NULL, it's considered to
388 * match all. If found, the resource is removed atomically, the
389 * release function called and the resource freed.
390 *
391 * RETURNS:
392 * 0 if devres is found and freed, -ENOENT if not found.
393 */
394int devres_release(struct device *dev, dr_release_t release,
395 dr_match_t match, void *match_data)
396{
397 void *res;
398
399 res = devres_remove(dev, release, match, match_data);
400 if (unlikely(!res))
401 return -ENOENT;
402
403 (*release)(dev, res);
404 devres_free(res);
405 return 0;
406}
407EXPORT_SYMBOL_GPL(devres_release);
408
409static int remove_nodes(struct device *dev,
410 struct list_head *first, struct list_head *end,
411 struct list_head *todo)
412{
413 int cnt = 0, nr_groups = 0;
414 struct list_head *cur;
415
416 /* First pass - move normal devres entries to @todo and clear
417 * devres_group colors.
418 */
419 cur = first;
420 while (cur != end) {
421 struct devres_node *node;
422 struct devres_group *grp;
423
424 node = list_entry(cur, struct devres_node, entry);
425 cur = cur->next;
426
427 grp = node_to_group(node);
428 if (grp) {
429 /* clear color of group markers in the first pass */
430 grp->color = 0;
431 nr_groups++;
432 } else {
433 /* regular devres entry */
434 if (&node->entry == first)
435 first = first->next;
436 list_move_tail(&node->entry, todo);
437 cnt++;
438 }
439 }
440
441 if (!nr_groups)
442 return cnt;
443
444 /* Second pass - Scan groups and color them. A group gets
445 * color value of two iff the group is wholly contained in
446 * [cur, end). That is, for a closed group, both opening and
447 * closing markers should be in the range, while just the
448 * opening marker is enough for an open group.
449 */
450 cur = first;
451 while (cur != end) {
452 struct devres_node *node;
453 struct devres_group *grp;
454
455 node = list_entry(cur, struct devres_node, entry);
456 cur = cur->next;
457
458 grp = node_to_group(node);
459 BUG_ON(!grp || list_empty(&grp->node[0].entry));
460
461 grp->color++;
462 if (list_empty(&grp->node[1].entry))
463 grp->color++;
464
465 BUG_ON(grp->color <= 0 || grp->color > 2);
466 if (grp->color == 2) {
467 /* No need to update cur or end. The removed
468 * nodes are always before both.
469 */
470 list_move_tail(&grp->node[0].entry, todo);
471 list_del_init(&grp->node[1].entry);
472 }
473 }
474
475 return cnt;
476}
477
478static int release_nodes(struct device *dev, struct list_head *first,
479 struct list_head *end, unsigned long flags)
480 __releases(&dev->devres_lock)
481{
482 LIST_HEAD(todo);
483 int cnt;
484 struct devres *dr, *tmp;
485
486 cnt = remove_nodes(dev, first, end, &todo);
487
488 spin_unlock_irqrestore(&dev->devres_lock, flags);
489
490 /* Release. Note that both devres and devres_group are
491 * handled as devres in the following loop. This is safe.
492 */
493 list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
494 devres_log(dev, &dr->node, "REL");
495 dr->node.release(dev, dr->data);
496 kfree(dr);
497 }
498
499 return cnt;
500}
501
502/**
503 * devres_release_all - Release all managed resources
504 * @dev: Device to release resources for
505 *
506 * Release all resources associated with @dev. This function is
507 * called on driver detach.
508 */
509int devres_release_all(struct device *dev)
510{
511 unsigned long flags;
512
513 /* Looks like an uninitialized device structure */
514 if (WARN_ON(dev->devres_head.next == NULL))
515 return -ENODEV;
516 spin_lock_irqsave(&dev->devres_lock, flags);
517 return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
518 flags);
519}
520
521/**
522 * devres_open_group - Open a new devres group
523 * @dev: Device to open devres group for
524 * @id: Separator ID
525 * @gfp: Allocation flags
526 *
527 * Open a new devres group for @dev with @id. For @id, using a
528 * pointer to an object which won't be used for another group is
529 * recommended. If @id is NULL, address-wise unique ID is created.
530 *
531 * RETURNS:
532 * ID of the new group, NULL on failure.
533 */
534void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
535{
536 struct devres_group *grp;
537 unsigned long flags;
538
539 grp = kmalloc(sizeof(*grp), gfp);
540 if (unlikely(!grp))
541 return NULL;
542
543 grp->node[0].release = &group_open_release;
544 grp->node[1].release = &group_close_release;
545 INIT_LIST_HEAD(&grp->node[0].entry);
546 INIT_LIST_HEAD(&grp->node[1].entry);
547 set_node_dbginfo(&grp->node[0], "grp<", 0);
548 set_node_dbginfo(&grp->node[1], "grp>", 0);
549 grp->id = grp;
550 if (id)
551 grp->id = id;
552
553 spin_lock_irqsave(&dev->devres_lock, flags);
554 add_dr(dev, &grp->node[0]);
555 spin_unlock_irqrestore(&dev->devres_lock, flags);
556 return grp->id;
557}
558EXPORT_SYMBOL_GPL(devres_open_group);
559
560/* Find devres group with ID @id. If @id is NULL, look for the latest. */
561static struct devres_group * find_group(struct device *dev, void *id)
562{
563 struct devres_node *node;
564
565 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
566 struct devres_group *grp;
567
568 if (node->release != &group_open_release)
569 continue;
570
571 grp = container_of(node, struct devres_group, node[0]);
572
573 if (id) {
574 if (grp->id == id)
575 return grp;
576 } else if (list_empty(&grp->node[1].entry))
577 return grp;
578 }
579
580 return NULL;
581}
582
583/**
584 * devres_close_group - Close a devres group
585 * @dev: Device to close devres group for
586 * @id: ID of target group, can be NULL
587 *
588 * Close the group identified by @id. If @id is NULL, the latest open
589 * group is selected.
590 */
591void devres_close_group(struct device *dev, void *id)
592{
593 struct devres_group *grp;
594 unsigned long flags;
595
596 spin_lock_irqsave(&dev->devres_lock, flags);
597
598 grp = find_group(dev, id);
599 if (grp)
600 add_dr(dev, &grp->node[1]);
601 else
602 WARN_ON(1);
603
604 spin_unlock_irqrestore(&dev->devres_lock, flags);
605}
606EXPORT_SYMBOL_GPL(devres_close_group);
607
608/**
609 * devres_remove_group - Remove a devres group
610 * @dev: Device to remove group for
611 * @id: ID of target group, can be NULL
612 *
613 * Remove the group identified by @id. If @id is NULL, the latest
614 * open group is selected. Note that removing a group doesn't affect
615 * any other resources.
616 */
617void devres_remove_group(struct device *dev, void *id)
618{
619 struct devres_group *grp;
620 unsigned long flags;
621
622 spin_lock_irqsave(&dev->devres_lock, flags);
623
624 grp = find_group(dev, id);
625 if (grp) {
626 list_del_init(&grp->node[0].entry);
627 list_del_init(&grp->node[1].entry);
628 devres_log(dev, &grp->node[0], "REM");
629 } else
630 WARN_ON(1);
631
632 spin_unlock_irqrestore(&dev->devres_lock, flags);
633
634 kfree(grp);
635}
636EXPORT_SYMBOL_GPL(devres_remove_group);
637
638/**
639 * devres_release_group - Release resources in a devres group
640 * @dev: Device to release group for
641 * @id: ID of target group, can be NULL
642 *
643 * Release all resources in the group identified by @id. If @id is
644 * NULL, the latest open group is selected. The selected group and
645 * groups properly nested inside the selected group are removed.
646 *
647 * RETURNS:
648 * The number of released non-group resources.
649 */
650int devres_release_group(struct device *dev, void *id)
651{
652 struct devres_group *grp;
653 unsigned long flags;
654 int cnt = 0;
655
656 spin_lock_irqsave(&dev->devres_lock, flags);
657
658 grp = find_group(dev, id);
659 if (grp) {
660 struct list_head *first = &grp->node[0].entry;
661 struct list_head *end = &dev->devres_head;
662
663 if (!list_empty(&grp->node[1].entry))
664 end = grp->node[1].entry.next;
665
666 cnt = release_nodes(dev, first, end, flags);
667 } else {
668 WARN_ON(1);
669 spin_unlock_irqrestore(&dev->devres_lock, flags);
670 }
671
672 return cnt;
673}
674EXPORT_SYMBOL_GPL(devres_release_group);
675
676/*
677 * Custom devres actions allow inserting a simple function call
678 * into the teadown sequence.
679 */
680
681struct action_devres {
682 void *data;
683 void (*action)(void *);
684};
685
686static int devm_action_match(struct device *dev, void *res, void *p)
687{
688 struct action_devres *devres = res;
689 struct action_devres *target = p;
690
691 return devres->action == target->action &&
692 devres->data == target->data;
693}
694
695static void devm_action_release(struct device *dev, void *res)
696{
697 struct action_devres *devres = res;
698
699 devres->action(devres->data);
700}
701
702/**
703 * devm_add_action() - add a custom action to list of managed resources
704 * @dev: Device that owns the action
705 * @action: Function that should be called
706 * @data: Pointer to data passed to @action implementation
707 *
708 * This adds a custom action to the list of managed resources so that
709 * it gets executed as part of standard resource unwinding.
710 */
711int devm_add_action(struct device *dev, void (*action)(void *), void *data)
712{
713 struct action_devres *devres;
714
715 devres = devres_alloc(devm_action_release,
716 sizeof(struct action_devres), GFP_KERNEL);
717 if (!devres)
718 return -ENOMEM;
719
720 devres->data = data;
721 devres->action = action;
722
723 devres_add(dev, devres);
724 return 0;
725}
726EXPORT_SYMBOL_GPL(devm_add_action);
727
728/**
729 * devm_remove_action() - removes previously added custom action
730 * @dev: Device that owns the action
731 * @action: Function implementing the action
732 * @data: Pointer to data passed to @action implementation
733 *
734 * Removes instance of @action previously added by devm_add_action().
735 * Both action and data should match one of the existing entries.
736 */
737void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
738{
739 struct action_devres devres = {
740 .data = data,
741 .action = action,
742 };
743
744 WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
745 &devres));
746
747}
748EXPORT_SYMBOL_GPL(devm_remove_action);
749
750/*
751 * Managed kmalloc/kfree
752 */
753static void devm_kmalloc_release(struct device *dev, void *res)
754{
755 /* noop */
756}
757
758static int devm_kmalloc_match(struct device *dev, void *res, void *data)
759{
760 return res == data;
761}
762
763/**
764 * devm_kmalloc - Resource-managed kmalloc
765 * @dev: Device to allocate memory for
766 * @size: Allocation size
767 * @gfp: Allocation gfp flags
768 *
769 * Managed kmalloc. Memory allocated with this function is
770 * automatically freed on driver detach. Like all other devres
771 * resources, guaranteed alignment is unsigned long long.
772 *
773 * RETURNS:
774 * Pointer to allocated memory on success, NULL on failure.
775 */
776void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
777{
778 struct devres *dr;
779
780 /* use raw alloc_dr for kmalloc caller tracing */
781 dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
782 if (unlikely(!dr))
783 return NULL;
784
785 /*
786 * This is named devm_kzalloc_release for historical reasons
787 * The initial implementation did not support kmalloc, only kzalloc
788 */
789 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
790 devres_add(dev, dr->data);
791 return dr->data;
792}
793EXPORT_SYMBOL_GPL(devm_kmalloc);
794
795/**
796 * devm_kstrdup - Allocate resource managed space and
797 * copy an existing string into that.
798 * @dev: Device to allocate memory for
799 * @s: the string to duplicate
800 * @gfp: the GFP mask used in the devm_kmalloc() call when
801 * allocating memory
802 * RETURNS:
803 * Pointer to allocated string on success, NULL on failure.
804 */
805char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
806{
807 size_t size;
808 char *buf;
809
810 if (!s)
811 return NULL;
812
813 size = strlen(s) + 1;
814 buf = devm_kmalloc(dev, size, gfp);
815 if (buf)
816 memcpy(buf, s, size);
817 return buf;
818}
819EXPORT_SYMBOL_GPL(devm_kstrdup);
820
821/**
822 * devm_kvasprintf - Allocate resource managed space and format a string
823 * into that.
824 * @dev: Device to allocate memory for
825 * @gfp: the GFP mask used in the devm_kmalloc() call when
826 * allocating memory
827 * @fmt: The printf()-style format string
828 * @ap: Arguments for the format string
829 * RETURNS:
830 * Pointer to allocated string on success, NULL on failure.
831 */
832char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
833 va_list ap)
834{
835 unsigned int len;
836 char *p;
837 va_list aq;
838
839 va_copy(aq, ap);
840 len = vsnprintf(NULL, 0, fmt, aq);
841 va_end(aq);
842
843 p = devm_kmalloc(dev, len+1, gfp);
844 if (!p)
845 return NULL;
846
847 vsnprintf(p, len+1, fmt, ap);
848
849 return p;
850}
851EXPORT_SYMBOL(devm_kvasprintf);
852
853/**
854 * devm_kasprintf - Allocate resource managed space and format a string
855 * into that.
856 * @dev: Device to allocate memory for
857 * @gfp: the GFP mask used in the devm_kmalloc() call when
858 * allocating memory
859 * @fmt: The printf()-style format string
860 * @...: Arguments for the format string
861 * RETURNS:
862 * Pointer to allocated string on success, NULL on failure.
863 */
864char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
865{
866 va_list ap;
867 char *p;
868
869 va_start(ap, fmt);
870 p = devm_kvasprintf(dev, gfp, fmt, ap);
871 va_end(ap);
872
873 return p;
874}
875EXPORT_SYMBOL_GPL(devm_kasprintf);
876
877/**
878 * devm_kfree - Resource-managed kfree
879 * @dev: Device this memory belongs to
880 * @p: Memory to free
881 *
882 * Free memory allocated with devm_kmalloc().
883 */
884void devm_kfree(struct device *dev, void *p)
885{
886 int rc;
887
888 rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);
889 WARN_ON(rc);
890}
891EXPORT_SYMBOL_GPL(devm_kfree);
892
893/**
894 * devm_kmemdup - Resource-managed kmemdup
895 * @dev: Device this memory belongs to
896 * @src: Memory region to duplicate
897 * @len: Memory region length
898 * @gfp: GFP mask to use
899 *
900 * Duplicate region of a memory using resource managed kmalloc
901 */
902void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
903{
904 void *p;
905
906 p = devm_kmalloc(dev, len, gfp);
907 if (p)
908 memcpy(p, src, len);
909
910 return p;
911}
912EXPORT_SYMBOL_GPL(devm_kmemdup);
913
914struct pages_devres {
915 unsigned long addr;
916 unsigned int order;
917};
918
919static int devm_pages_match(struct device *dev, void *res, void *p)
920{
921 struct pages_devres *devres = res;
922 struct pages_devres *target = p;
923
924 return devres->addr == target->addr;
925}
926
927static void devm_pages_release(struct device *dev, void *res)
928{
929 struct pages_devres *devres = res;
930
931 free_pages(devres->addr, devres->order);
932}
933
934/**
935 * devm_get_free_pages - Resource-managed __get_free_pages
936 * @dev: Device to allocate memory for
937 * @gfp_mask: Allocation gfp flags
938 * @order: Allocation size is (1 << order) pages
939 *
940 * Managed get_free_pages. Memory allocated with this function is
941 * automatically freed on driver detach.
942 *
943 * RETURNS:
944 * Address of allocated memory on success, 0 on failure.
945 */
946
947unsigned long devm_get_free_pages(struct device *dev,
948 gfp_t gfp_mask, unsigned int order)
949{
950 struct pages_devres *devres;
951 unsigned long addr;
952
953 addr = __get_free_pages(gfp_mask, order);
954
955 if (unlikely(!addr))
956 return 0;
957
958 devres = devres_alloc(devm_pages_release,
959 sizeof(struct pages_devres), GFP_KERNEL);
960 if (unlikely(!devres)) {
961 free_pages(addr, order);
962 return 0;
963 }
964
965 devres->addr = addr;
966 devres->order = order;
967
968 devres_add(dev, devres);
969 return addr;
970}
971EXPORT_SYMBOL_GPL(devm_get_free_pages);
972
973/**
974 * devm_free_pages - Resource-managed free_pages
975 * @dev: Device this memory belongs to
976 * @addr: Memory to free
977 *
978 * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
979 * there is no need to supply the @order.
980 */
981void devm_free_pages(struct device *dev, unsigned long addr)
982{
983 struct pages_devres devres = { .addr = addr };
984
985 WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
986 &devres));
987}
988EXPORT_SYMBOL_GPL(devm_free_pages);
989
990static void devm_percpu_release(struct device *dev, void *pdata)
991{
992 void __percpu *p;
993
994 p = *(void __percpu **)pdata;
995 free_percpu(p);
996}
997
998static int devm_percpu_match(struct device *dev, void *data, void *p)
999{
1000 struct devres *devr = container_of(data, struct devres, data);
1001
1002 return *(void **)devr->data == p;
1003}
1004
1005/**
1006 * __devm_alloc_percpu - Resource-managed alloc_percpu
1007 * @dev: Device to allocate per-cpu memory for
1008 * @size: Size of per-cpu memory to allocate
1009 * @align: Alignment of per-cpu memory to allocate
1010 *
1011 * Managed alloc_percpu. Per-cpu memory allocated with this function is
1012 * automatically freed on driver detach.
1013 *
1014 * RETURNS:
1015 * Pointer to allocated memory on success, NULL on failure.
1016 */
1017void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1018 size_t align)
1019{
1020 void *p;
1021 void __percpu *pcpu;
1022
1023 pcpu = __alloc_percpu(size, align);
1024 if (!pcpu)
1025 return NULL;
1026
1027 p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1028 if (!p) {
1029 free_percpu(pcpu);
1030 return NULL;
1031 }
1032
1033 *(void __percpu **)p = pcpu;
1034
1035 devres_add(dev, p);
1036
1037 return pcpu;
1038}
1039EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1040
1041/**
1042 * devm_free_percpu - Resource-managed free_percpu
1043 * @dev: Device this memory belongs to
1044 * @pdata: Per-cpu memory to free
1045 *
1046 * Free memory allocated with devm_alloc_percpu().
1047 */
1048void devm_free_percpu(struct device *dev, void __percpu *pdata)
1049{
1050 WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
1051 (void *)pdata));
1052}
1053EXPORT_SYMBOL_GPL(devm_free_percpu);