blob: 6683906647640da75238198ac47a07561fd131f9 [file] [log] [blame]
Tejun Heo9ac78492007-01-20 16:00:26 +09001/*
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090012#include <linux/slab.h>
Tejun Heo9ac78492007-01-20 16:00:26 +090013
Adrian Bunk2a013452007-06-18 01:42:54 +020014#include "base.h"
15
Tejun Heo9ac78492007-01-20 16:00:26 +090016struct 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))
Joe Perchesa369a7e2012-10-28 01:05:41 -070053 dev_err(dev, "DEVRES %3s %p %s (%lu bytes)\n",
54 op, node, node->name, (unsigned long)node->size);
Tejun Heo9ac78492007-01-20 16:00:26 +090055}
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
Tejun Heo9ac78492007-01-20 16:00:26 +0900107#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
Randy Dunlapd3e69752007-05-09 07:02:59 +0200121/**
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 */
Tejun Heo9ac78492007-01-20 16:00:26 +0900134void * 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/**
Ming Leibddb1b92012-08-04 12:01:26 +0800147 * devres_for_each_res - Resource iterator
148 * @dev: Device to iterate resource from
149 * @release: Look for resources associated with this release function
150 * @match: Match function (optional)
151 * @match_data: Data for the match function
152 * @fn: Function to be called for each matched resource.
153 * @data: Data for @fn, the 3rd parameter of @fn
154 *
155 * Call @fn for each devres of @dev which is associated with @release
156 * and for which @match returns 1.
157 *
158 * RETURNS:
159 * void
160 */
161void devres_for_each_res(struct device *dev, dr_release_t release,
162 dr_match_t match, void *match_data,
163 void (*fn)(struct device *, void *, void *),
164 void *data)
165{
166 struct devres_node *node;
167 struct devres_node *tmp;
168 unsigned long flags;
169
170 if (!fn)
171 return;
172
173 spin_lock_irqsave(&dev->devres_lock, flags);
174 list_for_each_entry_safe_reverse(node, tmp,
175 &dev->devres_head, entry) {
176 struct devres *dr = container_of(node, struct devres, node);
177
178 if (node->release != release)
179 continue;
180 if (match && !match(dev, dr->data, match_data))
181 continue;
182 fn(dev, dr->data, data);
183 }
184 spin_unlock_irqrestore(&dev->devres_lock, flags);
185}
186EXPORT_SYMBOL_GPL(devres_for_each_res);
187
188/**
Tejun Heo9ac78492007-01-20 16:00:26 +0900189 * devres_free - Free device resource data
190 * @res: Pointer to devres data to free
191 *
192 * Free devres created with devres_alloc().
193 */
194void devres_free(void *res)
195{
196 if (res) {
197 struct devres *dr = container_of(res, struct devres, data);
198
199 BUG_ON(!list_empty(&dr->node.entry));
200 kfree(dr);
201 }
202}
203EXPORT_SYMBOL_GPL(devres_free);
204
205/**
206 * devres_add - Register device resource
207 * @dev: Device to add resource to
208 * @res: Resource to register
209 *
210 * Register devres @res to @dev. @res should have been allocated
211 * using devres_alloc(). On driver detach, the associated release
212 * function will be invoked and devres will be freed automatically.
213 */
214void devres_add(struct device *dev, void *res)
215{
216 struct devres *dr = container_of(res, struct devres, data);
217 unsigned long flags;
218
219 spin_lock_irqsave(&dev->devres_lock, flags);
220 add_dr(dev, &dr->node);
221 spin_unlock_irqrestore(&dev->devres_lock, flags);
222}
223EXPORT_SYMBOL_GPL(devres_add);
224
225static struct devres *find_dr(struct device *dev, dr_release_t release,
226 dr_match_t match, void *match_data)
227{
228 struct devres_node *node;
229
230 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
231 struct devres *dr = container_of(node, struct devres, node);
232
233 if (node->release != release)
234 continue;
235 if (match && !match(dev, dr->data, match_data))
236 continue;
237 return dr;
238 }
239
240 return NULL;
241}
242
243/**
244 * devres_find - Find device resource
245 * @dev: Device to lookup resource from
246 * @release: Look for resources associated with this release function
247 * @match: Match function (optional)
248 * @match_data: Data for the match function
249 *
250 * Find the latest devres of @dev which is associated with @release
251 * and for which @match returns 1. If @match is NULL, it's considered
252 * to match all.
253 *
254 * RETURNS:
255 * Pointer to found devres, NULL if not found.
256 */
257void * devres_find(struct device *dev, dr_release_t release,
258 dr_match_t match, void *match_data)
259{
260 struct devres *dr;
261 unsigned long flags;
262
263 spin_lock_irqsave(&dev->devres_lock, flags);
264 dr = find_dr(dev, release, match, match_data);
265 spin_unlock_irqrestore(&dev->devres_lock, flags);
266
267 if (dr)
268 return dr->data;
269 return NULL;
270}
271EXPORT_SYMBOL_GPL(devres_find);
272
273/**
274 * devres_get - Find devres, if non-existent, add one atomically
275 * @dev: Device to lookup or add devres for
276 * @new_res: Pointer to new initialized devres to add if not found
277 * @match: Match function (optional)
278 * @match_data: Data for the match function
279 *
280 * Find the latest devres of @dev which has the same release function
281 * as @new_res and for which @match return 1. If found, @new_res is
282 * freed; otherwise, @new_res is added atomically.
283 *
284 * RETURNS:
285 * Pointer to found or added devres.
286 */
287void * devres_get(struct device *dev, void *new_res,
288 dr_match_t match, void *match_data)
289{
290 struct devres *new_dr = container_of(new_res, struct devres, data);
291 struct devres *dr;
292 unsigned long flags;
293
294 spin_lock_irqsave(&dev->devres_lock, flags);
295 dr = find_dr(dev, new_dr->node.release, match, match_data);
296 if (!dr) {
297 add_dr(dev, &new_dr->node);
298 dr = new_dr;
299 new_dr = NULL;
300 }
301 spin_unlock_irqrestore(&dev->devres_lock, flags);
302 devres_free(new_dr);
303
304 return dr->data;
305}
306EXPORT_SYMBOL_GPL(devres_get);
307
308/**
309 * devres_remove - Find a device resource and remove it
310 * @dev: Device to find resource from
311 * @release: Look for resources associated with this release function
312 * @match: Match function (optional)
313 * @match_data: Data for the match function
314 *
315 * Find the latest devres of @dev associated with @release and for
316 * which @match returns 1. If @match is NULL, it's considered to
317 * match all. If found, the resource is removed atomically and
318 * returned.
319 *
320 * RETURNS:
321 * Pointer to removed devres on success, NULL if not found.
322 */
323void * devres_remove(struct device *dev, dr_release_t release,
324 dr_match_t match, void *match_data)
325{
326 struct devres *dr;
327 unsigned long flags;
328
329 spin_lock_irqsave(&dev->devres_lock, flags);
330 dr = find_dr(dev, release, match, match_data);
331 if (dr) {
332 list_del_init(&dr->node.entry);
333 devres_log(dev, &dr->node, "REM");
334 }
335 spin_unlock_irqrestore(&dev->devres_lock, flags);
336
337 if (dr)
338 return dr->data;
339 return NULL;
340}
341EXPORT_SYMBOL_GPL(devres_remove);
342
343/**
344 * devres_destroy - Find a device resource and destroy it
345 * @dev: Device to find resource from
346 * @release: Look for resources associated with this release function
347 * @match: Match function (optional)
348 * @match_data: Data for the match function
349 *
350 * Find the latest devres of @dev associated with @release and for
351 * which @match returns 1. If @match is NULL, it's considered to
352 * match all. If found, the resource is removed atomically and freed.
353 *
Mark Brown698cd2d2012-05-03 18:15:12 +0100354 * Note that the release function for the resource will not be called,
355 * only the devres-allocated data will be freed. The caller becomes
356 * responsible for freeing any other data.
357 *
Tejun Heo9ac78492007-01-20 16:00:26 +0900358 * RETURNS:
359 * 0 if devres is found and freed, -ENOENT if not found.
360 */
361int devres_destroy(struct device *dev, dr_release_t release,
362 dr_match_t match, void *match_data)
363{
364 void *res;
365
366 res = devres_remove(dev, release, match, match_data);
367 if (unlikely(!res))
368 return -ENOENT;
369
370 devres_free(res);
371 return 0;
372}
373EXPORT_SYMBOL_GPL(devres_destroy);
374
Mark Brownd926d0e2012-05-03 18:15:13 +0100375
376/**
377 * devres_release - Find a device resource and destroy it, calling release
378 * @dev: Device to find resource from
379 * @release: Look for resources associated with this release function
380 * @match: Match function (optional)
381 * @match_data: Data for the match function
382 *
383 * Find the latest devres of @dev associated with @release and for
384 * which @match returns 1. If @match is NULL, it's considered to
385 * match all. If found, the resource is removed atomically, the
386 * release function called and the resource freed.
387 *
388 * RETURNS:
389 * 0 if devres is found and freed, -ENOENT if not found.
390 */
391int devres_release(struct device *dev, dr_release_t release,
392 dr_match_t match, void *match_data)
393{
394 void *res;
395
396 res = devres_remove(dev, release, match, match_data);
397 if (unlikely(!res))
398 return -ENOENT;
399
400 (*release)(dev, res);
401 devres_free(res);
402 return 0;
403}
404EXPORT_SYMBOL_GPL(devres_release);
405
Tejun Heo9ac78492007-01-20 16:00:26 +0900406static int remove_nodes(struct device *dev,
407 struct list_head *first, struct list_head *end,
408 struct list_head *todo)
409{
410 int cnt = 0, nr_groups = 0;
411 struct list_head *cur;
412
413 /* First pass - move normal devres entries to @todo and clear
414 * devres_group colors.
415 */
416 cur = first;
417 while (cur != end) {
418 struct devres_node *node;
419 struct devres_group *grp;
420
421 node = list_entry(cur, struct devres_node, entry);
422 cur = cur->next;
423
424 grp = node_to_group(node);
425 if (grp) {
426 /* clear color of group markers in the first pass */
427 grp->color = 0;
428 nr_groups++;
429 } else {
430 /* regular devres entry */
431 if (&node->entry == first)
432 first = first->next;
433 list_move_tail(&node->entry, todo);
434 cnt++;
435 }
436 }
437
438 if (!nr_groups)
439 return cnt;
440
441 /* Second pass - Scan groups and color them. A group gets
442 * color value of two iff the group is wholly contained in
443 * [cur, end). That is, for a closed group, both opening and
444 * closing markers should be in the range, while just the
445 * opening marker is enough for an open group.
446 */
447 cur = first;
448 while (cur != end) {
449 struct devres_node *node;
450 struct devres_group *grp;
451
452 node = list_entry(cur, struct devres_node, entry);
453 cur = cur->next;
454
455 grp = node_to_group(node);
456 BUG_ON(!grp || list_empty(&grp->node[0].entry));
457
458 grp->color++;
459 if (list_empty(&grp->node[1].entry))
460 grp->color++;
461
462 BUG_ON(grp->color <= 0 || grp->color > 2);
463 if (grp->color == 2) {
464 /* No need to update cur or end. The removed
465 * nodes are always before both.
466 */
467 list_move_tail(&grp->node[0].entry, todo);
468 list_del_init(&grp->node[1].entry);
469 }
470 }
471
472 return cnt;
473}
474
475static int release_nodes(struct device *dev, struct list_head *first,
476 struct list_head *end, unsigned long flags)
H Hartley Sweeten86ec67f2011-08-12 14:58:31 -0700477 __releases(&dev->devres_lock)
Tejun Heo9ac78492007-01-20 16:00:26 +0900478{
479 LIST_HEAD(todo);
480 int cnt;
481 struct devres *dr, *tmp;
482
483 cnt = remove_nodes(dev, first, end, &todo);
484
485 spin_unlock_irqrestore(&dev->devres_lock, flags);
486
487 /* Release. Note that both devres and devres_group are
488 * handled as devres in the following loop. This is safe.
489 */
490 list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
491 devres_log(dev, &dr->node, "REL");
492 dr->node.release(dev, dr->data);
493 kfree(dr);
494 }
495
496 return cnt;
497}
498
499/**
Randy Dunlapd3e69752007-05-09 07:02:59 +0200500 * devres_release_all - Release all managed resources
Tejun Heo9ac78492007-01-20 16:00:26 +0900501 * @dev: Device to release resources for
502 *
503 * Release all resources associated with @dev. This function is
504 * called on driver detach.
505 */
506int devres_release_all(struct device *dev)
507{
508 unsigned long flags;
509
Benjamin Herrenschmidteb8d3c62009-06-10 12:43:02 -0700510 /* Looks like an uninitialized device structure */
511 if (WARN_ON(dev->devres_head.next == NULL))
512 return -ENODEV;
Tejun Heo9ac78492007-01-20 16:00:26 +0900513 spin_lock_irqsave(&dev->devres_lock, flags);
514 return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
515 flags);
516}
517
518/**
519 * devres_open_group - Open a new devres group
520 * @dev: Device to open devres group for
521 * @id: Separator ID
522 * @gfp: Allocation flags
523 *
524 * Open a new devres group for @dev with @id. For @id, using a
525 * pointer to an object which won't be used for another group is
526 * recommended. If @id is NULL, address-wise unique ID is created.
527 *
528 * RETURNS:
529 * ID of the new group, NULL on failure.
530 */
531void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
532{
533 struct devres_group *grp;
534 unsigned long flags;
535
536 grp = kmalloc(sizeof(*grp), gfp);
537 if (unlikely(!grp))
538 return NULL;
539
540 grp->node[0].release = &group_open_release;
541 grp->node[1].release = &group_close_release;
542 INIT_LIST_HEAD(&grp->node[0].entry);
543 INIT_LIST_HEAD(&grp->node[1].entry);
544 set_node_dbginfo(&grp->node[0], "grp<", 0);
545 set_node_dbginfo(&grp->node[1], "grp>", 0);
546 grp->id = grp;
547 if (id)
548 grp->id = id;
549
550 spin_lock_irqsave(&dev->devres_lock, flags);
551 add_dr(dev, &grp->node[0]);
552 spin_unlock_irqrestore(&dev->devres_lock, flags);
553 return grp->id;
554}
555EXPORT_SYMBOL_GPL(devres_open_group);
556
557/* Find devres group with ID @id. If @id is NULL, look for the latest. */
558static struct devres_group * find_group(struct device *dev, void *id)
559{
560 struct devres_node *node;
561
562 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
563 struct devres_group *grp;
564
565 if (node->release != &group_open_release)
566 continue;
567
568 grp = container_of(node, struct devres_group, node[0]);
569
570 if (id) {
571 if (grp->id == id)
572 return grp;
573 } else if (list_empty(&grp->node[1].entry))
574 return grp;
575 }
576
577 return NULL;
578}
579
580/**
581 * devres_close_group - Close a devres group
582 * @dev: Device to close devres group for
583 * @id: ID of target group, can be NULL
584 *
585 * Close the group identified by @id. If @id is NULL, the latest open
586 * group is selected.
587 */
588void devres_close_group(struct device *dev, void *id)
589{
590 struct devres_group *grp;
591 unsigned long flags;
592
593 spin_lock_irqsave(&dev->devres_lock, flags);
594
595 grp = find_group(dev, id);
596 if (grp)
597 add_dr(dev, &grp->node[1]);
598 else
599 WARN_ON(1);
600
601 spin_unlock_irqrestore(&dev->devres_lock, flags);
602}
603EXPORT_SYMBOL_GPL(devres_close_group);
604
605/**
606 * devres_remove_group - Remove a devres group
607 * @dev: Device to remove group for
608 * @id: ID of target group, can be NULL
609 *
610 * Remove the group identified by @id. If @id is NULL, the latest
611 * open group is selected. Note that removing a group doesn't affect
612 * any other resources.
613 */
614void devres_remove_group(struct device *dev, void *id)
615{
616 struct devres_group *grp;
617 unsigned long flags;
618
619 spin_lock_irqsave(&dev->devres_lock, flags);
620
621 grp = find_group(dev, id);
622 if (grp) {
623 list_del_init(&grp->node[0].entry);
624 list_del_init(&grp->node[1].entry);
625 devres_log(dev, &grp->node[0], "REM");
626 } else
627 WARN_ON(1);
628
629 spin_unlock_irqrestore(&dev->devres_lock, flags);
630
631 kfree(grp);
632}
633EXPORT_SYMBOL_GPL(devres_remove_group);
634
635/**
636 * devres_release_group - Release resources in a devres group
637 * @dev: Device to release group for
638 * @id: ID of target group, can be NULL
639 *
640 * Release all resources in the group identified by @id. If @id is
641 * NULL, the latest open group is selected. The selected group and
642 * groups properly nested inside the selected group are removed.
643 *
644 * RETURNS:
645 * The number of released non-group resources.
646 */
647int devres_release_group(struct device *dev, void *id)
648{
649 struct devres_group *grp;
650 unsigned long flags;
651 int cnt = 0;
652
653 spin_lock_irqsave(&dev->devres_lock, flags);
654
655 grp = find_group(dev, id);
656 if (grp) {
657 struct list_head *first = &grp->node[0].entry;
658 struct list_head *end = &dev->devres_head;
659
660 if (!list_empty(&grp->node[1].entry))
661 end = grp->node[1].entry.next;
662
663 cnt = release_nodes(dev, first, end, flags);
664 } else {
665 WARN_ON(1);
666 spin_unlock_irqrestore(&dev->devres_lock, flags);
667 }
668
669 return cnt;
670}
671EXPORT_SYMBOL_GPL(devres_release_group);
672
673/*
674 * Managed kzalloc/kfree
675 */
676static void devm_kzalloc_release(struct device *dev, void *res)
677{
678 /* noop */
679}
680
681static int devm_kzalloc_match(struct device *dev, void *res, void *data)
682{
683 return res == data;
684}
685
686/**
Randy Dunlapd3e69752007-05-09 07:02:59 +0200687 * devm_kzalloc - Resource-managed kzalloc
Tejun Heo9ac78492007-01-20 16:00:26 +0900688 * @dev: Device to allocate memory for
689 * @size: Allocation size
690 * @gfp: Allocation gfp flags
691 *
692 * Managed kzalloc. Memory allocated with this function is
693 * automatically freed on driver detach. Like all other devres
694 * resources, guaranteed alignment is unsigned long long.
695 *
696 * RETURNS:
697 * Pointer to allocated memory on success, NULL on failure.
698 */
699void * devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
700{
701 struct devres *dr;
702
703 /* use raw alloc_dr for kmalloc caller tracing */
704 dr = alloc_dr(devm_kzalloc_release, size, gfp);
705 if (unlikely(!dr))
706 return NULL;
707
708 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
709 devres_add(dev, dr->data);
710 return dr->data;
711}
712EXPORT_SYMBOL_GPL(devm_kzalloc);
713
714/**
Randy Dunlapd3e69752007-05-09 07:02:59 +0200715 * devm_kfree - Resource-managed kfree
Tejun Heo9ac78492007-01-20 16:00:26 +0900716 * @dev: Device this memory belongs to
717 * @p: Memory to free
718 *
Axel Lin92f1b852011-12-20 15:17:45 +0800719 * Free memory allocated with devm_kzalloc().
Tejun Heo9ac78492007-01-20 16:00:26 +0900720 */
721void devm_kfree(struct device *dev, void *p)
722{
723 int rc;
724
725 rc = devres_destroy(dev, devm_kzalloc_release, devm_kzalloc_match, p);
726 WARN_ON(rc);
727}
728EXPORT_SYMBOL_GPL(devm_kfree);