projects/linux·blob v4.13 · refs

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1/*
2 * drivers/base/devres.c - device resource management
3 *
4 * Copyright (c) 2006 SUSE Linux Products GmbH
5 * Copyright (c) 2006 Tejun Heo <[email protected]>
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);