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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/*
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 * Note that the release function for the resource will not be called,
313 * only the devres-allocated data will be freed. The caller becomes
314 * responsible for freeing any other data.
315 *
316 * RETURNS:
317 * 0 if devres is found and freed, -ENOENT if not found.
318 */
319int devres_destroy(struct device *dev, dr_release_t release,
320 dr_match_t match, void *match_data)
321{
322 void *res;
323
324 res = devres_remove(dev, release, match, match_data);
325 if (unlikely(!res))
326 return -ENOENT;
327
328 devres_free(res);
329 return 0;
330}
331EXPORT_SYMBOL_GPL(devres_destroy);
332
333
334/**
335 * devres_release - Find a device resource and destroy it, calling release
336 * @dev: Device to find resource from
337 * @release: Look for resources associated with this release function
338 * @match: Match function (optional)
339 * @match_data: Data for the match function
340 *
341 * Find the latest devres of @dev associated with @release and for
342 * which @match returns 1. If @match is NULL, it's considered to
343 * match all. If found, the resource is removed atomically, the
344 * release function called and the resource freed.
345 *
346 * RETURNS:
347 * 0 if devres is found and freed, -ENOENT if not found.
348 */
349int devres_release(struct device *dev, dr_release_t release,
350 dr_match_t match, void *match_data)
351{
352 void *res;
353
354 res = devres_remove(dev, release, match, match_data);
355 if (unlikely(!res))
356 return -ENOENT;
357
358 (*release)(dev, res);
359 devres_free(res);
360 return 0;
361}
362EXPORT_SYMBOL_GPL(devres_release);
363
364static int remove_nodes(struct device *dev,
365 struct list_head *first, struct list_head *end,
366 struct list_head *todo)
367{
368 int cnt = 0, nr_groups = 0;
369 struct list_head *cur;
370
371 /* First pass - move normal devres entries to @todo and clear
372 * devres_group colors.
373 */
374 cur = first;
375 while (cur != end) {
376 struct devres_node *node;
377 struct devres_group *grp;
378
379 node = list_entry(cur, struct devres_node, entry);
380 cur = cur->next;
381
382 grp = node_to_group(node);
383 if (grp) {
384 /* clear color of group markers in the first pass */
385 grp->color = 0;
386 nr_groups++;
387 } else {
388 /* regular devres entry */
389 if (&node->entry == first)
390 first = first->next;
391 list_move_tail(&node->entry, todo);
392 cnt++;
393 }
394 }
395
396 if (!nr_groups)
397 return cnt;
398
399 /* Second pass - Scan groups and color them. A group gets
400 * color value of two iff the group is wholly contained in
401 * [cur, end). That is, for a closed group, both opening and
402 * closing markers should be in the range, while just the
403 * opening marker is enough for an open group.
404 */
405 cur = first;
406 while (cur != end) {
407 struct devres_node *node;
408 struct devres_group *grp;
409
410 node = list_entry(cur, struct devres_node, entry);
411 cur = cur->next;
412
413 grp = node_to_group(node);
414 BUG_ON(!grp || list_empty(&grp->node[0].entry));
415
416 grp->color++;
417 if (list_empty(&grp->node[1].entry))
418 grp->color++;
419
420 BUG_ON(grp->color <= 0 || grp->color > 2);
421 if (grp->color == 2) {
422 /* No need to update cur or end. The removed
423 * nodes are always before both.
424 */
425 list_move_tail(&grp->node[0].entry, todo);
426 list_del_init(&grp->node[1].entry);
427 }
428 }
429
430 return cnt;
431}
432
433static int release_nodes(struct device *dev, struct list_head *first,
434 struct list_head *end, unsigned long flags)
435 __releases(&dev->devres_lock)
436{
437 LIST_HEAD(todo);
438 int cnt;
439 struct devres *dr, *tmp;
440
441 cnt = remove_nodes(dev, first, end, &todo);
442
443 spin_unlock_irqrestore(&dev->devres_lock, flags);
444
445 /* Release. Note that both devres and devres_group are
446 * handled as devres in the following loop. This is safe.
447 */
448 list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
449 devres_log(dev, &dr->node, "REL");
450 dr->node.release(dev, dr->data);
451 kfree(dr);
452 }
453
454 return cnt;
455}
456
457/**
458 * devres_release_all - Release all managed resources
459 * @dev: Device to release resources for
460 *
461 * Release all resources associated with @dev. This function is
462 * called on driver detach.
463 */
464int devres_release_all(struct device *dev)
465{
466 unsigned long flags;
467
468 /* Looks like an uninitialized device structure */
469 if (WARN_ON(dev->devres_head.next == NULL))
470 return -ENODEV;
471 spin_lock_irqsave(&dev->devres_lock, flags);
472 return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
473 flags);
474}
475
476/**
477 * devres_open_group - Open a new devres group
478 * @dev: Device to open devres group for
479 * @id: Separator ID
480 * @gfp: Allocation flags
481 *
482 * Open a new devres group for @dev with @id. For @id, using a
483 * pointer to an object which won't be used for another group is
484 * recommended. If @id is NULL, address-wise unique ID is created.
485 *
486 * RETURNS:
487 * ID of the new group, NULL on failure.
488 */
489void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
490{
491 struct devres_group *grp;
492 unsigned long flags;
493
494 grp = kmalloc(sizeof(*grp), gfp);
495 if (unlikely(!grp))
496 return NULL;
497
498 grp->node[0].release = &group_open_release;
499 grp->node[1].release = &group_close_release;
500 INIT_LIST_HEAD(&grp->node[0].entry);
501 INIT_LIST_HEAD(&grp->node[1].entry);
502 set_node_dbginfo(&grp->node[0], "grp<", 0);
503 set_node_dbginfo(&grp->node[1], "grp>", 0);
504 grp->id = grp;
505 if (id)
506 grp->id = id;
507
508 spin_lock_irqsave(&dev->devres_lock, flags);
509 add_dr(dev, &grp->node[0]);
510 spin_unlock_irqrestore(&dev->devres_lock, flags);
511 return grp->id;
512}
513EXPORT_SYMBOL_GPL(devres_open_group);
514
515/* Find devres group with ID @id. If @id is NULL, look for the latest. */
516static struct devres_group * find_group(struct device *dev, void *id)
517{
518 struct devres_node *node;
519
520 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
521 struct devres_group *grp;
522
523 if (node->release != &group_open_release)
524 continue;
525
526 grp = container_of(node, struct devres_group, node[0]);
527
528 if (id) {
529 if (grp->id == id)
530 return grp;
531 } else if (list_empty(&grp->node[1].entry))
532 return grp;
533 }
534
535 return NULL;
536}
537
538/**
539 * devres_close_group - Close a devres group
540 * @dev: Device to close devres group for
541 * @id: ID of target group, can be NULL
542 *
543 * Close the group identified by @id. If @id is NULL, the latest open
544 * group is selected.
545 */
546void devres_close_group(struct device *dev, void *id)
547{
548 struct devres_group *grp;
549 unsigned long flags;
550
551 spin_lock_irqsave(&dev->devres_lock, flags);
552
553 grp = find_group(dev, id);
554 if (grp)
555 add_dr(dev, &grp->node[1]);
556 else
557 WARN_ON(1);
558
559 spin_unlock_irqrestore(&dev->devres_lock, flags);
560}
561EXPORT_SYMBOL_GPL(devres_close_group);
562
563/**
564 * devres_remove_group - Remove a devres group
565 * @dev: Device to remove group for
566 * @id: ID of target group, can be NULL
567 *
568 * Remove the group identified by @id. If @id is NULL, the latest
569 * open group is selected. Note that removing a group doesn't affect
570 * any other resources.
571 */
572void devres_remove_group(struct device *dev, void *id)
573{
574 struct devres_group *grp;
575 unsigned long flags;
576
577 spin_lock_irqsave(&dev->devres_lock, flags);
578
579 grp = find_group(dev, id);
580 if (grp) {
581 list_del_init(&grp->node[0].entry);
582 list_del_init(&grp->node[1].entry);
583 devres_log(dev, &grp->node[0], "REM");
584 } else
585 WARN_ON(1);
586
587 spin_unlock_irqrestore(&dev->devres_lock, flags);
588
589 kfree(grp);
590}
591EXPORT_SYMBOL_GPL(devres_remove_group);
592
593/**
594 * devres_release_group - Release resources in a devres group
595 * @dev: Device to release group for
596 * @id: ID of target group, can be NULL
597 *
598 * Release all resources in the group identified by @id. If @id is
599 * NULL, the latest open group is selected. The selected group and
600 * groups properly nested inside the selected group are removed.
601 *
602 * RETURNS:
603 * The number of released non-group resources.
604 */
605int devres_release_group(struct device *dev, void *id)
606{
607 struct devres_group *grp;
608 unsigned long flags;
609 int cnt = 0;
610
611 spin_lock_irqsave(&dev->devres_lock, flags);
612
613 grp = find_group(dev, id);
614 if (grp) {
615 struct list_head *first = &grp->node[0].entry;
616 struct list_head *end = &dev->devres_head;
617
618 if (!list_empty(&grp->node[1].entry))
619 end = grp->node[1].entry.next;
620
621 cnt = release_nodes(dev, first, end, flags);
622 } else {
623 WARN_ON(1);
624 spin_unlock_irqrestore(&dev->devres_lock, flags);
625 }
626
627 return cnt;
628}
629EXPORT_SYMBOL_GPL(devres_release_group);
630
631/*
632 * Managed kzalloc/kfree
633 */
634static void devm_kzalloc_release(struct device *dev, void *res)
635{
636 /* noop */
637}
638
639static int devm_kzalloc_match(struct device *dev, void *res, void *data)
640{
641 return res == data;
642}
643
644/**
645 * devm_kzalloc - Resource-managed kzalloc
646 * @dev: Device to allocate memory for
647 * @size: Allocation size
648 * @gfp: Allocation gfp flags
649 *
650 * Managed kzalloc. Memory allocated with this function is
651 * automatically freed on driver detach. Like all other devres
652 * resources, guaranteed alignment is unsigned long long.
653 *
654 * RETURNS:
655 * Pointer to allocated memory on success, NULL on failure.
656 */
657void * devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
658{
659 struct devres *dr;
660
661 /* use raw alloc_dr for kmalloc caller tracing */
662 dr = alloc_dr(devm_kzalloc_release, size, gfp);
663 if (unlikely(!dr))
664 return NULL;
665
666 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
667 devres_add(dev, dr->data);
668 return dr->data;
669}
670EXPORT_SYMBOL_GPL(devm_kzalloc);
671
672/**
673 * devm_kfree - Resource-managed kfree
674 * @dev: Device this memory belongs to
675 * @p: Memory to free
676 *
677 * Free memory allocated with devm_kzalloc().
678 */
679void devm_kfree(struct device *dev, void *p)
680{
681 int rc;
682
683 rc = devres_destroy(dev, devm_kzalloc_release, devm_kzalloc_match, p);
684 WARN_ON(rc);
685}
686EXPORT_SYMBOL_GPL(devm_kfree);