Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/drivers/base/devres.c

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

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