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9ac7849e TH |
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 | ||
13 | struct devres_node { | |
14 | struct list_head entry; | |
15 | dr_release_t release; | |
16 | #ifdef CONFIG_DEBUG_DEVRES | |
17 | const char *name; | |
18 | size_t size; | |
19 | #endif | |
20 | }; | |
21 | ||
22 | struct devres { | |
23 | struct devres_node node; | |
24 | /* -- 3 pointers */ | |
25 | unsigned long long data[]; /* guarantee ull alignment */ | |
26 | }; | |
27 | ||
28 | struct devres_group { | |
29 | struct devres_node node[2]; | |
30 | void *id; | |
31 | int color; | |
32 | /* -- 8 pointers */ | |
33 | }; | |
34 | ||
35 | #ifdef CONFIG_DEBUG_DEVRES | |
36 | static int log_devres = 0; | |
37 | module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR); | |
38 | ||
39 | static void set_node_dbginfo(struct devres_node *node, const char *name, | |
40 | size_t size) | |
41 | { | |
42 | node->name = name; | |
43 | node->size = size; | |
44 | } | |
45 | ||
46 | static void devres_log(struct device *dev, struct devres_node *node, | |
47 | const char *op) | |
48 | { | |
49 | if (unlikely(log_devres)) | |
50 | dev_printk(KERN_ERR, dev, "DEVRES %3s %p %s (%lu bytes)\n", | |
51 | op, node, node->name, (unsigned long)node->size); | |
52 | } | |
53 | #else /* CONFIG_DEBUG_DEVRES */ | |
54 | #define set_node_dbginfo(node, n, s) do {} while (0) | |
55 | #define devres_log(dev, node, op) do {} while (0) | |
56 | #endif /* CONFIG_DEBUG_DEVRES */ | |
57 | ||
58 | /* | |
59 | * Release functions for devres group. These callbacks are used only | |
60 | * for identification. | |
61 | */ | |
62 | static void group_open_release(struct device *dev, void *res) | |
63 | { | |
64 | /* noop */ | |
65 | } | |
66 | ||
67 | static void group_close_release(struct device *dev, void *res) | |
68 | { | |
69 | /* noop */ | |
70 | } | |
71 | ||
72 | static struct devres_group * node_to_group(struct devres_node *node) | |
73 | { | |
74 | if (node->release == &group_open_release) | |
75 | return container_of(node, struct devres_group, node[0]); | |
76 | if (node->release == &group_close_release) | |
77 | return container_of(node, struct devres_group, node[1]); | |
78 | return NULL; | |
79 | } | |
80 | ||
81 | static __always_inline struct devres * alloc_dr(dr_release_t release, | |
82 | size_t size, gfp_t gfp) | |
83 | { | |
84 | size_t tot_size = sizeof(struct devres) + size; | |
85 | struct devres *dr; | |
86 | ||
87 | dr = kmalloc_track_caller(tot_size, gfp); | |
88 | if (unlikely(!dr)) | |
89 | return NULL; | |
90 | ||
91 | memset(dr, 0, tot_size); | |
92 | INIT_LIST_HEAD(&dr->node.entry); | |
93 | dr->node.release = release; | |
94 | return dr; | |
95 | } | |
96 | ||
97 | static void add_dr(struct device *dev, struct devres_node *node) | |
98 | { | |
99 | devres_log(dev, node, "ADD"); | |
100 | BUG_ON(!list_empty(&node->entry)); | |
101 | list_add_tail(&node->entry, &dev->devres_head); | |
102 | } | |
103 | ||
104 | /** | |
105 | * devres_alloc - Allocate device resource data | |
106 | * @release: Release function devres will be associated with | |
107 | * @size: Allocation size | |
108 | * @gfp: Allocation flags | |
109 | * | |
110 | * allocate devres of @size bytes. The allocated area is zeroed, then | |
111 | * associated with @release. The returned pointer can be passed to | |
112 | * other devres_*() functions. | |
113 | * | |
114 | * RETURNS: | |
115 | * Pointer to allocated devres on success, NULL on failure. | |
116 | */ | |
117 | #ifdef CONFIG_DEBUG_DEVRES | |
118 | void * __devres_alloc(dr_release_t release, size_t size, gfp_t gfp, | |
119 | const char *name) | |
120 | { | |
121 | struct devres *dr; | |
122 | ||
123 | dr = alloc_dr(release, size, gfp); | |
124 | if (unlikely(!dr)) | |
125 | return NULL; | |
126 | set_node_dbginfo(&dr->node, name, size); | |
127 | return dr->data; | |
128 | } | |
129 | EXPORT_SYMBOL_GPL(__devres_alloc); | |
130 | #else | |
131 | void * devres_alloc(dr_release_t release, size_t size, gfp_t gfp) | |
132 | { | |
133 | struct devres *dr; | |
134 | ||
135 | dr = alloc_dr(release, size, gfp); | |
136 | if (unlikely(!dr)) | |
137 | return NULL; | |
138 | return dr->data; | |
139 | } | |
140 | EXPORT_SYMBOL_GPL(devres_alloc); | |
141 | #endif | |
142 | ||
143 | /** | |
144 | * devres_free - Free device resource data | |
145 | * @res: Pointer to devres data to free | |
146 | * | |
147 | * Free devres created with devres_alloc(). | |
148 | */ | |
149 | void devres_free(void *res) | |
150 | { | |
151 | if (res) { | |
152 | struct devres *dr = container_of(res, struct devres, data); | |
153 | ||
154 | BUG_ON(!list_empty(&dr->node.entry)); | |
155 | kfree(dr); | |
156 | } | |
157 | } | |
158 | EXPORT_SYMBOL_GPL(devres_free); | |
159 | ||
160 | /** | |
161 | * devres_add - Register device resource | |
162 | * @dev: Device to add resource to | |
163 | * @res: Resource to register | |
164 | * | |
165 | * Register devres @res to @dev. @res should have been allocated | |
166 | * using devres_alloc(). On driver detach, the associated release | |
167 | * function will be invoked and devres will be freed automatically. | |
168 | */ | |
169 | void devres_add(struct device *dev, void *res) | |
170 | { | |
171 | struct devres *dr = container_of(res, struct devres, data); | |
172 | unsigned long flags; | |
173 | ||
174 | spin_lock_irqsave(&dev->devres_lock, flags); | |
175 | add_dr(dev, &dr->node); | |
176 | spin_unlock_irqrestore(&dev->devres_lock, flags); | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(devres_add); | |
179 | ||
180 | static struct devres *find_dr(struct device *dev, dr_release_t release, | |
181 | dr_match_t match, void *match_data) | |
182 | { | |
183 | struct devres_node *node; | |
184 | ||
185 | list_for_each_entry_reverse(node, &dev->devres_head, entry) { | |
186 | struct devres *dr = container_of(node, struct devres, node); | |
187 | ||
188 | if (node->release != release) | |
189 | continue; | |
190 | if (match && !match(dev, dr->data, match_data)) | |
191 | continue; | |
192 | return dr; | |
193 | } | |
194 | ||
195 | return NULL; | |
196 | } | |
197 | ||
198 | /** | |
199 | * devres_find - Find device resource | |
200 | * @dev: Device to lookup resource from | |
201 | * @release: Look for resources associated with this release function | |
202 | * @match: Match function (optional) | |
203 | * @match_data: Data for the match function | |
204 | * | |
205 | * Find the latest devres of @dev which is associated with @release | |
206 | * and for which @match returns 1. If @match is NULL, it's considered | |
207 | * to match all. | |
208 | * | |
209 | * RETURNS: | |
210 | * Pointer to found devres, NULL if not found. | |
211 | */ | |
212 | void * devres_find(struct device *dev, dr_release_t release, | |
213 | dr_match_t match, void *match_data) | |
214 | { | |
215 | struct devres *dr; | |
216 | unsigned long flags; | |
217 | ||
218 | spin_lock_irqsave(&dev->devres_lock, flags); | |
219 | dr = find_dr(dev, release, match, match_data); | |
220 | spin_unlock_irqrestore(&dev->devres_lock, flags); | |
221 | ||
222 | if (dr) | |
223 | return dr->data; | |
224 | return NULL; | |
225 | } | |
226 | EXPORT_SYMBOL_GPL(devres_find); | |
227 | ||
228 | /** | |
229 | * devres_get - Find devres, if non-existent, add one atomically | |
230 | * @dev: Device to lookup or add devres for | |
231 | * @new_res: Pointer to new initialized devres to add if not found | |
232 | * @match: Match function (optional) | |
233 | * @match_data: Data for the match function | |
234 | * | |
235 | * Find the latest devres of @dev which has the same release function | |
236 | * as @new_res and for which @match return 1. If found, @new_res is | |
237 | * freed; otherwise, @new_res is added atomically. | |
238 | * | |
239 | * RETURNS: | |
240 | * Pointer to found or added devres. | |
241 | */ | |
242 | void * devres_get(struct device *dev, void *new_res, | |
243 | dr_match_t match, void *match_data) | |
244 | { | |
245 | struct devres *new_dr = container_of(new_res, struct devres, data); | |
246 | struct devres *dr; | |
247 | unsigned long flags; | |
248 | ||
249 | spin_lock_irqsave(&dev->devres_lock, flags); | |
250 | dr = find_dr(dev, new_dr->node.release, match, match_data); | |
251 | if (!dr) { | |
252 | add_dr(dev, &new_dr->node); | |
253 | dr = new_dr; | |
254 | new_dr = NULL; | |
255 | } | |
256 | spin_unlock_irqrestore(&dev->devres_lock, flags); | |
257 | devres_free(new_dr); | |
258 | ||
259 | return dr->data; | |
260 | } | |
261 | EXPORT_SYMBOL_GPL(devres_get); | |
262 | ||
263 | /** | |
264 | * devres_remove - Find a device resource and remove it | |
265 | * @dev: Device to find resource from | |
266 | * @release: Look for resources associated with this release function | |
267 | * @match: Match function (optional) | |
268 | * @match_data: Data for the match function | |
269 | * | |
270 | * Find the latest devres of @dev associated with @release and for | |
271 | * which @match returns 1. If @match is NULL, it's considered to | |
272 | * match all. If found, the resource is removed atomically and | |
273 | * returned. | |
274 | * | |
275 | * RETURNS: | |
276 | * Pointer to removed devres on success, NULL if not found. | |
277 | */ | |
278 | void * devres_remove(struct device *dev, dr_release_t release, | |
279 | dr_match_t match, void *match_data) | |
280 | { | |
281 | struct devres *dr; | |
282 | unsigned long flags; | |
283 | ||
284 | spin_lock_irqsave(&dev->devres_lock, flags); | |
285 | dr = find_dr(dev, release, match, match_data); | |
286 | if (dr) { | |
287 | list_del_init(&dr->node.entry); | |
288 | devres_log(dev, &dr->node, "REM"); | |
289 | } | |
290 | spin_unlock_irqrestore(&dev->devres_lock, flags); | |
291 | ||
292 | if (dr) | |
293 | return dr->data; | |
294 | return NULL; | |
295 | } | |
296 | EXPORT_SYMBOL_GPL(devres_remove); | |
297 | ||
298 | /** | |
299 | * devres_destroy - Find a device resource and destroy it | |
300 | * @dev: Device to find resource from | |
301 | * @release: Look for resources associated with this release function | |
302 | * @match: Match function (optional) | |
303 | * @match_data: Data for the match function | |
304 | * | |
305 | * Find the latest devres of @dev associated with @release and for | |
306 | * which @match returns 1. If @match is NULL, it's considered to | |
307 | * match all. If found, the resource is removed atomically and freed. | |
308 | * | |
309 | * RETURNS: | |
310 | * 0 if devres is found and freed, -ENOENT if not found. | |
311 | */ | |
312 | int devres_destroy(struct device *dev, dr_release_t release, | |
313 | dr_match_t match, void *match_data) | |
314 | { | |
315 | void *res; | |
316 | ||
317 | res = devres_remove(dev, release, match, match_data); | |
318 | if (unlikely(!res)) | |
319 | return -ENOENT; | |
320 | ||
321 | devres_free(res); | |
322 | return 0; | |
323 | } | |
324 | EXPORT_SYMBOL_GPL(devres_destroy); | |
325 | ||
326 | static int remove_nodes(struct device *dev, | |
327 | struct list_head *first, struct list_head *end, | |
328 | struct list_head *todo) | |
329 | { | |
330 | int cnt = 0, nr_groups = 0; | |
331 | struct list_head *cur; | |
332 | ||
333 | /* First pass - move normal devres entries to @todo and clear | |
334 | * devres_group colors. | |
335 | */ | |
336 | cur = first; | |
337 | while (cur != end) { | |
338 | struct devres_node *node; | |
339 | struct devres_group *grp; | |
340 | ||
341 | node = list_entry(cur, struct devres_node, entry); | |
342 | cur = cur->next; | |
343 | ||
344 | grp = node_to_group(node); | |
345 | if (grp) { | |
346 | /* clear color of group markers in the first pass */ | |
347 | grp->color = 0; | |
348 | nr_groups++; | |
349 | } else { | |
350 | /* regular devres entry */ | |
351 | if (&node->entry == first) | |
352 | first = first->next; | |
353 | list_move_tail(&node->entry, todo); | |
354 | cnt++; | |
355 | } | |
356 | } | |
357 | ||
358 | if (!nr_groups) | |
359 | return cnt; | |
360 | ||
361 | /* Second pass - Scan groups and color them. A group gets | |
362 | * color value of two iff the group is wholly contained in | |
363 | * [cur, end). That is, for a closed group, both opening and | |
364 | * closing markers should be in the range, while just the | |
365 | * opening marker is enough for an open group. | |
366 | */ | |
367 | cur = first; | |
368 | while (cur != end) { | |
369 | struct devres_node *node; | |
370 | struct devres_group *grp; | |
371 | ||
372 | node = list_entry(cur, struct devres_node, entry); | |
373 | cur = cur->next; | |
374 | ||
375 | grp = node_to_group(node); | |
376 | BUG_ON(!grp || list_empty(&grp->node[0].entry)); | |
377 | ||
378 | grp->color++; | |
379 | if (list_empty(&grp->node[1].entry)) | |
380 | grp->color++; | |
381 | ||
382 | BUG_ON(grp->color <= 0 || grp->color > 2); | |
383 | if (grp->color == 2) { | |
384 | /* No need to update cur or end. The removed | |
385 | * nodes are always before both. | |
386 | */ | |
387 | list_move_tail(&grp->node[0].entry, todo); | |
388 | list_del_init(&grp->node[1].entry); | |
389 | } | |
390 | } | |
391 | ||
392 | return cnt; | |
393 | } | |
394 | ||
395 | static int release_nodes(struct device *dev, struct list_head *first, | |
396 | struct list_head *end, unsigned long flags) | |
397 | { | |
398 | LIST_HEAD(todo); | |
399 | int cnt; | |
400 | struct devres *dr, *tmp; | |
401 | ||
402 | cnt = remove_nodes(dev, first, end, &todo); | |
403 | ||
404 | spin_unlock_irqrestore(&dev->devres_lock, flags); | |
405 | ||
406 | /* Release. Note that both devres and devres_group are | |
407 | * handled as devres in the following loop. This is safe. | |
408 | */ | |
409 | list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) { | |
410 | devres_log(dev, &dr->node, "REL"); | |
411 | dr->node.release(dev, dr->data); | |
412 | kfree(dr); | |
413 | } | |
414 | ||
415 | return cnt; | |
416 | } | |
417 | ||
418 | /** | |
419 | * devres_release_all - Release all resources | |
420 | * @dev: Device to release resources for | |
421 | * | |
422 | * Release all resources associated with @dev. This function is | |
423 | * called on driver detach. | |
424 | */ | |
425 | int devres_release_all(struct device *dev) | |
426 | { | |
427 | unsigned long flags; | |
428 | ||
429 | spin_lock_irqsave(&dev->devres_lock, flags); | |
430 | return release_nodes(dev, dev->devres_head.next, &dev->devres_head, | |
431 | flags); | |
432 | } | |
433 | ||
434 | /** | |
435 | * devres_open_group - Open a new devres group | |
436 | * @dev: Device to open devres group for | |
437 | * @id: Separator ID | |
438 | * @gfp: Allocation flags | |
439 | * | |
440 | * Open a new devres group for @dev with @id. For @id, using a | |
441 | * pointer to an object which won't be used for another group is | |
442 | * recommended. If @id is NULL, address-wise unique ID is created. | |
443 | * | |
444 | * RETURNS: | |
445 | * ID of the new group, NULL on failure. | |
446 | */ | |
447 | void * devres_open_group(struct device *dev, void *id, gfp_t gfp) | |
448 | { | |
449 | struct devres_group *grp; | |
450 | unsigned long flags; | |
451 | ||
452 | grp = kmalloc(sizeof(*grp), gfp); | |
453 | if (unlikely(!grp)) | |
454 | return NULL; | |
455 | ||
456 | grp->node[0].release = &group_open_release; | |
457 | grp->node[1].release = &group_close_release; | |
458 | INIT_LIST_HEAD(&grp->node[0].entry); | |
459 | INIT_LIST_HEAD(&grp->node[1].entry); | |
460 | set_node_dbginfo(&grp->node[0], "grp<", 0); | |
461 | set_node_dbginfo(&grp->node[1], "grp>", 0); | |
462 | grp->id = grp; | |
463 | if (id) | |
464 | grp->id = id; | |
465 | ||
466 | spin_lock_irqsave(&dev->devres_lock, flags); | |
467 | add_dr(dev, &grp->node[0]); | |
468 | spin_unlock_irqrestore(&dev->devres_lock, flags); | |
469 | return grp->id; | |
470 | } | |
471 | EXPORT_SYMBOL_GPL(devres_open_group); | |
472 | ||
473 | /* Find devres group with ID @id. If @id is NULL, look for the latest. */ | |
474 | static struct devres_group * find_group(struct device *dev, void *id) | |
475 | { | |
476 | struct devres_node *node; | |
477 | ||
478 | list_for_each_entry_reverse(node, &dev->devres_head, entry) { | |
479 | struct devres_group *grp; | |
480 | ||
481 | if (node->release != &group_open_release) | |
482 | continue; | |
483 | ||
484 | grp = container_of(node, struct devres_group, node[0]); | |
485 | ||
486 | if (id) { | |
487 | if (grp->id == id) | |
488 | return grp; | |
489 | } else if (list_empty(&grp->node[1].entry)) | |
490 | return grp; | |
491 | } | |
492 | ||
493 | return NULL; | |
494 | } | |
495 | ||
496 | /** | |
497 | * devres_close_group - Close a devres group | |
498 | * @dev: Device to close devres group for | |
499 | * @id: ID of target group, can be NULL | |
500 | * | |
501 | * Close the group identified by @id. If @id is NULL, the latest open | |
502 | * group is selected. | |
503 | */ | |
504 | void devres_close_group(struct device *dev, void *id) | |
505 | { | |
506 | struct devres_group *grp; | |
507 | unsigned long flags; | |
508 | ||
509 | spin_lock_irqsave(&dev->devres_lock, flags); | |
510 | ||
511 | grp = find_group(dev, id); | |
512 | if (grp) | |
513 | add_dr(dev, &grp->node[1]); | |
514 | else | |
515 | WARN_ON(1); | |
516 | ||
517 | spin_unlock_irqrestore(&dev->devres_lock, flags); | |
518 | } | |
519 | EXPORT_SYMBOL_GPL(devres_close_group); | |
520 | ||
521 | /** | |
522 | * devres_remove_group - Remove a devres group | |
523 | * @dev: Device to remove group for | |
524 | * @id: ID of target group, can be NULL | |
525 | * | |
526 | * Remove the group identified by @id. If @id is NULL, the latest | |
527 | * open group is selected. Note that removing a group doesn't affect | |
528 | * any other resources. | |
529 | */ | |
530 | void devres_remove_group(struct device *dev, void *id) | |
531 | { | |
532 | struct devres_group *grp; | |
533 | unsigned long flags; | |
534 | ||
535 | spin_lock_irqsave(&dev->devres_lock, flags); | |
536 | ||
537 | grp = find_group(dev, id); | |
538 | if (grp) { | |
539 | list_del_init(&grp->node[0].entry); | |
540 | list_del_init(&grp->node[1].entry); | |
541 | devres_log(dev, &grp->node[0], "REM"); | |
542 | } else | |
543 | WARN_ON(1); | |
544 | ||
545 | spin_unlock_irqrestore(&dev->devres_lock, flags); | |
546 | ||
547 | kfree(grp); | |
548 | } | |
549 | EXPORT_SYMBOL_GPL(devres_remove_group); | |
550 | ||
551 | /** | |
552 | * devres_release_group - Release resources in a devres group | |
553 | * @dev: Device to release group for | |
554 | * @id: ID of target group, can be NULL | |
555 | * | |
556 | * Release all resources in the group identified by @id. If @id is | |
557 | * NULL, the latest open group is selected. The selected group and | |
558 | * groups properly nested inside the selected group are removed. | |
559 | * | |
560 | * RETURNS: | |
561 | * The number of released non-group resources. | |
562 | */ | |
563 | int devres_release_group(struct device *dev, void *id) | |
564 | { | |
565 | struct devres_group *grp; | |
566 | unsigned long flags; | |
567 | int cnt = 0; | |
568 | ||
569 | spin_lock_irqsave(&dev->devres_lock, flags); | |
570 | ||
571 | grp = find_group(dev, id); | |
572 | if (grp) { | |
573 | struct list_head *first = &grp->node[0].entry; | |
574 | struct list_head *end = &dev->devres_head; | |
575 | ||
576 | if (!list_empty(&grp->node[1].entry)) | |
577 | end = grp->node[1].entry.next; | |
578 | ||
579 | cnt = release_nodes(dev, first, end, flags); | |
580 | } else { | |
581 | WARN_ON(1); | |
582 | spin_unlock_irqrestore(&dev->devres_lock, flags); | |
583 | } | |
584 | ||
585 | return cnt; | |
586 | } | |
587 | EXPORT_SYMBOL_GPL(devres_release_group); | |
588 | ||
589 | /* | |
590 | * Managed kzalloc/kfree | |
591 | */ | |
592 | static void devm_kzalloc_release(struct device *dev, void *res) | |
593 | { | |
594 | /* noop */ | |
595 | } | |
596 | ||
597 | static int devm_kzalloc_match(struct device *dev, void *res, void *data) | |
598 | { | |
599 | return res == data; | |
600 | } | |
601 | ||
602 | /** | |
603 | * devm_kzalloc - Managed kzalloc | |
604 | * @dev: Device to allocate memory for | |
605 | * @size: Allocation size | |
606 | * @gfp: Allocation gfp flags | |
607 | * | |
608 | * Managed kzalloc. Memory allocated with this function is | |
609 | * automatically freed on driver detach. Like all other devres | |
610 | * resources, guaranteed alignment is unsigned long long. | |
611 | * | |
612 | * RETURNS: | |
613 | * Pointer to allocated memory on success, NULL on failure. | |
614 | */ | |
615 | void * devm_kzalloc(struct device *dev, size_t size, gfp_t gfp) | |
616 | { | |
617 | struct devres *dr; | |
618 | ||
619 | /* use raw alloc_dr for kmalloc caller tracing */ | |
620 | dr = alloc_dr(devm_kzalloc_release, size, gfp); | |
621 | if (unlikely(!dr)) | |
622 | return NULL; | |
623 | ||
624 | set_node_dbginfo(&dr->node, "devm_kzalloc_release", size); | |
625 | devres_add(dev, dr->data); | |
626 | return dr->data; | |
627 | } | |
628 | EXPORT_SYMBOL_GPL(devm_kzalloc); | |
629 | ||
630 | /** | |
631 | * devm_kfree - Managed kfree | |
632 | * @dev: Device this memory belongs to | |
633 | * @p: Memory to free | |
634 | * | |
635 | * Free memory allocated with dev_kzalloc(). | |
636 | */ | |
637 | void devm_kfree(struct device *dev, void *p) | |
638 | { | |
639 | int rc; | |
640 | ||
641 | rc = devres_destroy(dev, devm_kzalloc_release, devm_kzalloc_match, p); | |
642 | WARN_ON(rc); | |
643 | } | |
644 | EXPORT_SYMBOL_GPL(devm_kfree); |