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