driver core: remove drivers/base/sys.c and include/linux/sysdev.h
[zen-stable.git] / drivers / base / devres.c
blob524bf96c289f0abe8d677712b79635b3456b1ddf
1 /*
2 * drivers/base/devres.c - device resource management
4 * Copyright (c) 2006 SUSE Linux Products GmbH
5 * Copyright (c) 2006 Tejun Heo <teheo@suse.de>
7 * This file is released under the GPLv2.
8 */
10 #include <linux/device.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
14 #include "base.h"
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
25 struct devres {
26 struct devres_node node;
27 /* -- 3 pointers */
28 unsigned long long data[]; /* guarantee ull alignment */
31 struct devres_group {
32 struct devres_node node[2];
33 void *id;
34 int color;
35 /* -- 8 pointers */
38 #ifdef CONFIG_DEBUG_DEVRES
39 static int log_devres = 0;
40 module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
42 static void set_node_dbginfo(struct devres_node *node, const char *name,
43 size_t size)
45 node->name = name;
46 node->size = size;
49 static void devres_log(struct device *dev, struct devres_node *node,
50 const char *op)
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);
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 */
62 * Release functions for devres group. These callbacks are used only
63 * for identification.
65 static void group_open_release(struct device *dev, void *res)
67 /* noop */
70 static void group_close_release(struct device *dev, void *res)
72 /* noop */
75 static struct devres_group * node_to_group(struct devres_node *node)
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;
84 static __always_inline struct devres * alloc_dr(dr_release_t release,
85 size_t size, gfp_t gfp)
87 size_t tot_size = sizeof(struct devres) + size;
88 struct devres *dr;
90 dr = kmalloc_track_caller(tot_size, gfp);
91 if (unlikely(!dr))
92 return NULL;
94 memset(dr, 0, tot_size);
95 INIT_LIST_HEAD(&dr->node.entry);
96 dr->node.release = release;
97 return dr;
100 static void add_dr(struct device *dev, struct devres_node *node)
102 devres_log(dev, node, "ADD");
103 BUG_ON(!list_empty(&node->entry));
104 list_add_tail(&node->entry, &dev->devres_head);
107 #ifdef CONFIG_DEBUG_DEVRES
108 void * __devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
109 const char *name)
111 struct devres *dr;
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;
119 EXPORT_SYMBOL_GPL(__devres_alloc);
120 #else
122 * devres_alloc - Allocate device resource data
123 * @release: Release function devres will be associated with
124 * @size: Allocation size
125 * @gfp: Allocation flags
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.
131 * RETURNS:
132 * Pointer to allocated devres on success, NULL on failure.
134 void * devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
136 struct devres *dr;
138 dr = alloc_dr(release, size, gfp);
139 if (unlikely(!dr))
140 return NULL;
141 return dr->data;
143 EXPORT_SYMBOL_GPL(devres_alloc);
144 #endif
147 * devres_free - Free device resource data
148 * @res: Pointer to devres data to free
150 * Free devres created with devres_alloc().
152 void devres_free(void *res)
154 if (res) {
155 struct devres *dr = container_of(res, struct devres, data);
157 BUG_ON(!list_empty(&dr->node.entry));
158 kfree(dr);
161 EXPORT_SYMBOL_GPL(devres_free);
164 * devres_add - Register device resource
165 * @dev: Device to add resource to
166 * @res: Resource to register
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.
172 void devres_add(struct device *dev, void *res)
174 struct devres *dr = container_of(res, struct devres, data);
175 unsigned long flags;
177 spin_lock_irqsave(&dev->devres_lock, flags);
178 add_dr(dev, &dr->node);
179 spin_unlock_irqrestore(&dev->devres_lock, flags);
181 EXPORT_SYMBOL_GPL(devres_add);
183 static struct devres *find_dr(struct device *dev, dr_release_t release,
184 dr_match_t match, void *match_data)
186 struct devres_node *node;
188 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
189 struct devres *dr = container_of(node, struct devres, node);
191 if (node->release != release)
192 continue;
193 if (match && !match(dev, dr->data, match_data))
194 continue;
195 return dr;
198 return NULL;
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
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.
212 * RETURNS:
213 * Pointer to found devres, NULL if not found.
215 void * devres_find(struct device *dev, dr_release_t release,
216 dr_match_t match, void *match_data)
218 struct devres *dr;
219 unsigned long flags;
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);
225 if (dr)
226 return dr->data;
227 return NULL;
229 EXPORT_SYMBOL_GPL(devres_find);
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
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.
242 * RETURNS:
243 * Pointer to found or added devres.
245 void * devres_get(struct device *dev, void *new_res,
246 dr_match_t match, void *match_data)
248 struct devres *new_dr = container_of(new_res, struct devres, data);
249 struct devres *dr;
250 unsigned long flags;
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;
259 spin_unlock_irqrestore(&dev->devres_lock, flags);
260 devres_free(new_dr);
262 return dr->data;
264 EXPORT_SYMBOL_GPL(devres_get);
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
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.
278 * RETURNS:
279 * Pointer to removed devres on success, NULL if not found.
281 void * devres_remove(struct device *dev, dr_release_t release,
282 dr_match_t match, void *match_data)
284 struct devres *dr;
285 unsigned long flags;
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");
293 spin_unlock_irqrestore(&dev->devres_lock, flags);
295 if (dr)
296 return dr->data;
297 return NULL;
299 EXPORT_SYMBOL_GPL(devres_remove);
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
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.
312 * RETURNS:
313 * 0 if devres is found and freed, -ENOENT if not found.
315 int devres_destroy(struct device *dev, dr_release_t release,
316 dr_match_t match, void *match_data)
318 void *res;
320 res = devres_remove(dev, release, match, match_data);
321 if (unlikely(!res))
322 return -ENOENT;
324 devres_free(res);
325 return 0;
327 EXPORT_SYMBOL_GPL(devres_destroy);
329 static int remove_nodes(struct device *dev,
330 struct list_head *first, struct list_head *end,
331 struct list_head *todo)
333 int cnt = 0, nr_groups = 0;
334 struct list_head *cur;
336 /* First pass - move normal devres entries to @todo and clear
337 * devres_group colors.
339 cur = first;
340 while (cur != end) {
341 struct devres_node *node;
342 struct devres_group *grp;
344 node = list_entry(cur, struct devres_node, entry);
345 cur = cur->next;
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++;
361 if (!nr_groups)
362 return cnt;
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.
370 cur = first;
371 while (cur != end) {
372 struct devres_node *node;
373 struct devres_group *grp;
375 node = list_entry(cur, struct devres_node, entry);
376 cur = cur->next;
378 grp = node_to_group(node);
379 BUG_ON(!grp || list_empty(&grp->node[0].entry));
381 grp->color++;
382 if (list_empty(&grp->node[1].entry))
383 grp->color++;
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.
390 list_move_tail(&grp->node[0].entry, todo);
391 list_del_init(&grp->node[1].entry);
395 return cnt;
398 static int release_nodes(struct device *dev, struct list_head *first,
399 struct list_head *end, unsigned long flags)
400 __releases(&dev->devres_lock)
402 LIST_HEAD(todo);
403 int cnt;
404 struct devres *dr, *tmp;
406 cnt = remove_nodes(dev, first, end, &todo);
408 spin_unlock_irqrestore(&dev->devres_lock, flags);
410 /* Release. Note that both devres and devres_group are
411 * handled as devres in the following loop. This is safe.
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);
419 return cnt;
423 * devres_release_all - Release all managed resources
424 * @dev: Device to release resources for
426 * Release all resources associated with @dev. This function is
427 * called on driver detach.
429 int devres_release_all(struct device *dev)
431 unsigned long flags;
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);
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
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.
451 * RETURNS:
452 * ID of the new group, NULL on failure.
454 void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
456 struct devres_group *grp;
457 unsigned long flags;
459 grp = kmalloc(sizeof(*grp), gfp);
460 if (unlikely(!grp))
461 return NULL;
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;
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;
478 EXPORT_SYMBOL_GPL(devres_open_group);
480 /* Find devres group with ID @id. If @id is NULL, look for the latest. */
481 static struct devres_group * find_group(struct device *dev, void *id)
483 struct devres_node *node;
485 list_for_each_entry_reverse(node, &dev->devres_head, entry) {
486 struct devres_group *grp;
488 if (node->release != &group_open_release)
489 continue;
491 grp = container_of(node, struct devres_group, node[0]);
493 if (id) {
494 if (grp->id == id)
495 return grp;
496 } else if (list_empty(&grp->node[1].entry))
497 return grp;
500 return NULL;
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
508 * Close the group identified by @id. If @id is NULL, the latest open
509 * group is selected.
511 void devres_close_group(struct device *dev, void *id)
513 struct devres_group *grp;
514 unsigned long flags;
516 spin_lock_irqsave(&dev->devres_lock, flags);
518 grp = find_group(dev, id);
519 if (grp)
520 add_dr(dev, &grp->node[1]);
521 else
522 WARN_ON(1);
524 spin_unlock_irqrestore(&dev->devres_lock, flags);
526 EXPORT_SYMBOL_GPL(devres_close_group);
529 * devres_remove_group - Remove a devres group
530 * @dev: Device to remove group for
531 * @id: ID of target group, can be NULL
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.
537 void devres_remove_group(struct device *dev, void *id)
539 struct devres_group *grp;
540 unsigned long flags;
542 spin_lock_irqsave(&dev->devres_lock, flags);
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);
552 spin_unlock_irqrestore(&dev->devres_lock, flags);
554 kfree(grp);
556 EXPORT_SYMBOL_GPL(devres_remove_group);
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
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.
567 * RETURNS:
568 * The number of released non-group resources.
570 int devres_release_group(struct device *dev, void *id)
572 struct devres_group *grp;
573 unsigned long flags;
574 int cnt = 0;
576 spin_lock_irqsave(&dev->devres_lock, flags);
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;
583 if (!list_empty(&grp->node[1].entry))
584 end = grp->node[1].entry.next;
586 cnt = release_nodes(dev, first, end, flags);
587 } else {
588 WARN_ON(1);
589 spin_unlock_irqrestore(&dev->devres_lock, flags);
592 return cnt;
594 EXPORT_SYMBOL_GPL(devres_release_group);
597 * Managed kzalloc/kfree
599 static void devm_kzalloc_release(struct device *dev, void *res)
601 /* noop */
604 static int devm_kzalloc_match(struct device *dev, void *res, void *data)
606 return res == data;
610 * devm_kzalloc - Resource-managed kzalloc
611 * @dev: Device to allocate memory for
612 * @size: Allocation size
613 * @gfp: Allocation gfp flags
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.
619 * RETURNS:
620 * Pointer to allocated memory on success, NULL on failure.
622 void * devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
624 struct devres *dr;
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;
631 set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
632 devres_add(dev, dr->data);
633 return dr->data;
635 EXPORT_SYMBOL_GPL(devm_kzalloc);
638 * devm_kfree - Resource-managed kfree
639 * @dev: Device this memory belongs to
640 * @p: Memory to free
642 * Free memory allocated with devm_kzalloc().
644 void devm_kfree(struct device *dev, void *p)
646 int rc;
648 rc = devres_destroy(dev, devm_kzalloc_release, devm_kzalloc_match, p);
649 WARN_ON(rc);
651 EXPORT_SYMBOL_GPL(devm_kfree);