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11f1ceca GD |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Interconnect framework core driver | |
4 | * | |
5 | * Copyright (c) 2017-2019, Linaro Ltd. | |
6 | * Author: Georgi Djakov <georgi.djakov@linaro.org> | |
7 | */ | |
8 | ||
9 | #include <linux/device.h> | |
10 | #include <linux/idr.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/interconnect.h> | |
13 | #include <linux/interconnect-provider.h> | |
14 | #include <linux/list.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/mutex.h> | |
17 | #include <linux/slab.h> | |
87e3031b | 18 | #include <linux/of.h> |
11f1ceca GD |
19 | #include <linux/overflow.h> |
20 | ||
21 | static DEFINE_IDR(icc_idr); | |
22 | static LIST_HEAD(icc_providers); | |
23 | static DEFINE_MUTEX(icc_lock); | |
24 | ||
25 | /** | |
26 | * struct icc_req - constraints that are attached to each node | |
27 | * @req_node: entry in list of requests for the particular @node | |
28 | * @node: the interconnect node to which this constraint applies | |
29 | * @dev: reference to the device that sets the constraints | |
30 | * @avg_bw: an integer describing the average bandwidth in kBps | |
31 | * @peak_bw: an integer describing the peak bandwidth in kBps | |
32 | */ | |
33 | struct icc_req { | |
34 | struct hlist_node req_node; | |
35 | struct icc_node *node; | |
36 | struct device *dev; | |
37 | u32 avg_bw; | |
38 | u32 peak_bw; | |
39 | }; | |
40 | ||
41 | /** | |
42 | * struct icc_path - interconnect path structure | |
43 | * @num_nodes: number of hops (nodes) | |
44 | * @reqs: array of the requests applicable to this path of nodes | |
45 | */ | |
46 | struct icc_path { | |
47 | size_t num_nodes; | |
48 | struct icc_req reqs[]; | |
49 | }; | |
50 | ||
51 | static struct icc_node *node_find(const int id) | |
52 | { | |
53 | return idr_find(&icc_idr, id); | |
54 | } | |
55 | ||
56 | static struct icc_path *path_init(struct device *dev, struct icc_node *dst, | |
57 | ssize_t num_nodes) | |
58 | { | |
59 | struct icc_node *node = dst; | |
60 | struct icc_path *path; | |
61 | int i; | |
62 | ||
63 | path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL); | |
64 | if (!path) | |
65 | return ERR_PTR(-ENOMEM); | |
66 | ||
67 | path->num_nodes = num_nodes; | |
68 | ||
69 | for (i = num_nodes - 1; i >= 0; i--) { | |
70 | node->provider->users++; | |
71 | hlist_add_head(&path->reqs[i].req_node, &node->req_list); | |
72 | path->reqs[i].node = node; | |
73 | path->reqs[i].dev = dev; | |
74 | /* reference to previous node was saved during path traversal */ | |
75 | node = node->reverse; | |
76 | } | |
77 | ||
78 | return path; | |
79 | } | |
80 | ||
81 | static struct icc_path *path_find(struct device *dev, struct icc_node *src, | |
82 | struct icc_node *dst) | |
83 | { | |
84 | struct icc_path *path = ERR_PTR(-EPROBE_DEFER); | |
85 | struct icc_node *n, *node = NULL; | |
86 | struct list_head traverse_list; | |
87 | struct list_head edge_list; | |
88 | struct list_head visited_list; | |
89 | size_t i, depth = 1; | |
90 | bool found = false; | |
91 | ||
92 | INIT_LIST_HEAD(&traverse_list); | |
93 | INIT_LIST_HEAD(&edge_list); | |
94 | INIT_LIST_HEAD(&visited_list); | |
95 | ||
96 | list_add(&src->search_list, &traverse_list); | |
97 | src->reverse = NULL; | |
98 | ||
99 | do { | |
100 | list_for_each_entry_safe(node, n, &traverse_list, search_list) { | |
101 | if (node == dst) { | |
102 | found = true; | |
103 | list_splice_init(&edge_list, &visited_list); | |
104 | list_splice_init(&traverse_list, &visited_list); | |
105 | break; | |
106 | } | |
107 | for (i = 0; i < node->num_links; i++) { | |
108 | struct icc_node *tmp = node->links[i]; | |
109 | ||
110 | if (!tmp) { | |
111 | path = ERR_PTR(-ENOENT); | |
112 | goto out; | |
113 | } | |
114 | ||
115 | if (tmp->is_traversed) | |
116 | continue; | |
117 | ||
118 | tmp->is_traversed = true; | |
119 | tmp->reverse = node; | |
120 | list_add_tail(&tmp->search_list, &edge_list); | |
121 | } | |
122 | } | |
123 | ||
124 | if (found) | |
125 | break; | |
126 | ||
127 | list_splice_init(&traverse_list, &visited_list); | |
128 | list_splice_init(&edge_list, &traverse_list); | |
129 | ||
130 | /* count the hops including the source */ | |
131 | depth++; | |
132 | ||
133 | } while (!list_empty(&traverse_list)); | |
134 | ||
135 | out: | |
136 | ||
137 | /* reset the traversed state */ | |
138 | list_for_each_entry_reverse(n, &visited_list, search_list) | |
139 | n->is_traversed = false; | |
140 | ||
141 | if (found) | |
142 | path = path_init(dev, dst, depth); | |
143 | ||
144 | return path; | |
145 | } | |
146 | ||
147 | /* | |
148 | * We want the path to honor all bandwidth requests, so the average and peak | |
149 | * bandwidth requirements from each consumer are aggregated at each node. | |
150 | * The aggregation is platform specific, so each platform can customize it by | |
151 | * implementing its own aggregate() function. | |
152 | */ | |
153 | ||
154 | static int aggregate_requests(struct icc_node *node) | |
155 | { | |
156 | struct icc_provider *p = node->provider; | |
157 | struct icc_req *r; | |
158 | ||
159 | node->avg_bw = 0; | |
160 | node->peak_bw = 0; | |
161 | ||
162 | hlist_for_each_entry(r, &node->req_list, req_node) | |
163 | p->aggregate(node, r->avg_bw, r->peak_bw, | |
164 | &node->avg_bw, &node->peak_bw); | |
165 | ||
166 | return 0; | |
167 | } | |
168 | ||
169 | static int apply_constraints(struct icc_path *path) | |
170 | { | |
171 | struct icc_node *next, *prev = NULL; | |
172 | int ret = -EINVAL; | |
173 | int i; | |
174 | ||
175 | for (i = 0; i < path->num_nodes; i++) { | |
176 | next = path->reqs[i].node; | |
177 | ||
178 | /* | |
179 | * Both endpoints should be valid master-slave pairs of the | |
180 | * same interconnect provider that will be configured. | |
181 | */ | |
182 | if (!prev || next->provider != prev->provider) { | |
183 | prev = next; | |
184 | continue; | |
185 | } | |
186 | ||
187 | /* set the constraints */ | |
188 | ret = next->provider->set(prev, next); | |
189 | if (ret) | |
190 | goto out; | |
191 | ||
192 | prev = next; | |
193 | } | |
194 | out: | |
195 | return ret; | |
196 | } | |
197 | ||
87e3031b GD |
198 | /* of_icc_xlate_onecell() - Translate function using a single index. |
199 | * @spec: OF phandle args to map into an interconnect node. | |
200 | * @data: private data (pointer to struct icc_onecell_data) | |
201 | * | |
202 | * This is a generic translate function that can be used to model simple | |
203 | * interconnect providers that have one device tree node and provide | |
204 | * multiple interconnect nodes. A single cell is used as an index into | |
205 | * an array of icc nodes specified in the icc_onecell_data struct when | |
206 | * registering the provider. | |
207 | */ | |
208 | struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec, | |
209 | void *data) | |
210 | { | |
211 | struct icc_onecell_data *icc_data = data; | |
212 | unsigned int idx = spec->args[0]; | |
213 | ||
214 | if (idx >= icc_data->num_nodes) { | |
215 | pr_err("%s: invalid index %u\n", __func__, idx); | |
216 | return ERR_PTR(-EINVAL); | |
217 | } | |
218 | ||
219 | return icc_data->nodes[idx]; | |
220 | } | |
221 | EXPORT_SYMBOL_GPL(of_icc_xlate_onecell); | |
222 | ||
223 | /** | |
224 | * of_icc_get_from_provider() - Look-up interconnect node | |
225 | * @spec: OF phandle args to use for look-up | |
226 | * | |
227 | * Looks for interconnect provider under the node specified by @spec and if | |
228 | * found, uses xlate function of the provider to map phandle args to node. | |
229 | * | |
230 | * Returns a valid pointer to struct icc_node on success or ERR_PTR() | |
231 | * on failure. | |
232 | */ | |
233 | static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec) | |
234 | { | |
235 | struct icc_node *node = ERR_PTR(-EPROBE_DEFER); | |
236 | struct icc_provider *provider; | |
237 | ||
238 | if (!spec || spec->args_count != 1) | |
239 | return ERR_PTR(-EINVAL); | |
240 | ||
241 | mutex_lock(&icc_lock); | |
242 | list_for_each_entry(provider, &icc_providers, provider_list) { | |
243 | if (provider->dev->of_node == spec->np) | |
244 | node = provider->xlate(spec, provider->data); | |
245 | if (!IS_ERR(node)) | |
246 | break; | |
247 | } | |
248 | mutex_unlock(&icc_lock); | |
249 | ||
250 | return node; | |
251 | } | |
252 | ||
253 | /** | |
254 | * of_icc_get() - get a path handle from a DT node based on name | |
255 | * @dev: device pointer for the consumer device | |
256 | * @name: interconnect path name | |
257 | * | |
258 | * This function will search for a path between two endpoints and return an | |
259 | * icc_path handle on success. Use icc_put() to release constraints when they | |
260 | * are not needed anymore. | |
261 | * If the interconnect API is disabled, NULL is returned and the consumer | |
262 | * drivers will still build. Drivers are free to handle this specifically, | |
263 | * but they don't have to. | |
264 | * | |
265 | * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned | |
266 | * when the API is disabled or the "interconnects" DT property is missing. | |
267 | */ | |
268 | struct icc_path *of_icc_get(struct device *dev, const char *name) | |
269 | { | |
270 | struct icc_path *path = ERR_PTR(-EPROBE_DEFER); | |
271 | struct icc_node *src_node, *dst_node; | |
272 | struct device_node *np = NULL; | |
273 | struct of_phandle_args src_args, dst_args; | |
274 | int idx = 0; | |
275 | int ret; | |
276 | ||
277 | if (!dev || !dev->of_node) | |
278 | return ERR_PTR(-ENODEV); | |
279 | ||
280 | np = dev->of_node; | |
281 | ||
282 | /* | |
283 | * When the consumer DT node do not have "interconnects" property | |
284 | * return a NULL path to skip setting constraints. | |
285 | */ | |
286 | if (!of_find_property(np, "interconnects", NULL)) | |
287 | return NULL; | |
288 | ||
289 | /* | |
290 | * We use a combination of phandle and specifier for endpoint. For now | |
291 | * lets support only global ids and extend this in the future if needed | |
292 | * without breaking DT compatibility. | |
293 | */ | |
294 | if (name) { | |
295 | idx = of_property_match_string(np, "interconnect-names", name); | |
296 | if (idx < 0) | |
297 | return ERR_PTR(idx); | |
298 | } | |
299 | ||
300 | ret = of_parse_phandle_with_args(np, "interconnects", | |
301 | "#interconnect-cells", idx * 2, | |
302 | &src_args); | |
303 | if (ret) | |
304 | return ERR_PTR(ret); | |
305 | ||
306 | of_node_put(src_args.np); | |
307 | ||
308 | ret = of_parse_phandle_with_args(np, "interconnects", | |
309 | "#interconnect-cells", idx * 2 + 1, | |
310 | &dst_args); | |
311 | if (ret) | |
312 | return ERR_PTR(ret); | |
313 | ||
314 | of_node_put(dst_args.np); | |
315 | ||
316 | src_node = of_icc_get_from_provider(&src_args); | |
317 | ||
318 | if (IS_ERR(src_node)) { | |
319 | if (PTR_ERR(src_node) != -EPROBE_DEFER) | |
320 | dev_err(dev, "error finding src node: %ld\n", | |
321 | PTR_ERR(src_node)); | |
322 | return ERR_CAST(src_node); | |
323 | } | |
324 | ||
325 | dst_node = of_icc_get_from_provider(&dst_args); | |
326 | ||
327 | if (IS_ERR(dst_node)) { | |
328 | if (PTR_ERR(dst_node) != -EPROBE_DEFER) | |
329 | dev_err(dev, "error finding dst node: %ld\n", | |
330 | PTR_ERR(dst_node)); | |
331 | return ERR_CAST(dst_node); | |
332 | } | |
333 | ||
334 | mutex_lock(&icc_lock); | |
335 | path = path_find(dev, src_node, dst_node); | |
336 | if (IS_ERR(path)) | |
337 | dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); | |
338 | mutex_unlock(&icc_lock); | |
339 | ||
340 | return path; | |
341 | } | |
342 | EXPORT_SYMBOL_GPL(of_icc_get); | |
343 | ||
11f1ceca GD |
344 | /** |
345 | * icc_set_bw() - set bandwidth constraints on an interconnect path | |
346 | * @path: reference to the path returned by icc_get() | |
347 | * @avg_bw: average bandwidth in kilobytes per second | |
348 | * @peak_bw: peak bandwidth in kilobytes per second | |
349 | * | |
350 | * This function is used by an interconnect consumer to express its own needs | |
351 | * in terms of bandwidth for a previously requested path between two endpoints. | |
352 | * The requests are aggregated and each node is updated accordingly. The entire | |
353 | * path is locked by a mutex to ensure that the set() is completed. | |
354 | * The @path can be NULL when the "interconnects" DT properties is missing, | |
355 | * which will mean that no constraints will be set. | |
356 | * | |
357 | * Returns 0 on success, or an appropriate error code otherwise. | |
358 | */ | |
359 | int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw) | |
360 | { | |
361 | struct icc_node *node; | |
362 | size_t i; | |
363 | int ret; | |
364 | ||
365 | if (!path) | |
366 | return 0; | |
367 | ||
368 | mutex_lock(&icc_lock); | |
369 | ||
370 | for (i = 0; i < path->num_nodes; i++) { | |
371 | node = path->reqs[i].node; | |
372 | ||
373 | /* update the consumer request for this path */ | |
374 | path->reqs[i].avg_bw = avg_bw; | |
375 | path->reqs[i].peak_bw = peak_bw; | |
376 | ||
377 | /* aggregate requests for this node */ | |
378 | aggregate_requests(node); | |
379 | } | |
380 | ||
381 | ret = apply_constraints(path); | |
382 | if (ret) | |
383 | pr_debug("interconnect: error applying constraints (%d)\n", | |
384 | ret); | |
385 | ||
386 | mutex_unlock(&icc_lock); | |
387 | ||
388 | return ret; | |
389 | } | |
390 | EXPORT_SYMBOL_GPL(icc_set_bw); | |
391 | ||
392 | /** | |
393 | * icc_get() - return a handle for path between two endpoints | |
394 | * @dev: the device requesting the path | |
395 | * @src_id: source device port id | |
396 | * @dst_id: destination device port id | |
397 | * | |
398 | * This function will search for a path between two endpoints and return an | |
399 | * icc_path handle on success. Use icc_put() to release | |
400 | * constraints when they are not needed anymore. | |
401 | * If the interconnect API is disabled, NULL is returned and the consumer | |
402 | * drivers will still build. Drivers are free to handle this specifically, | |
403 | * but they don't have to. | |
404 | * | |
405 | * Return: icc_path pointer on success, ERR_PTR() on error or NULL if the | |
406 | * interconnect API is disabled. | |
407 | */ | |
408 | struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id) | |
409 | { | |
410 | struct icc_node *src, *dst; | |
411 | struct icc_path *path = ERR_PTR(-EPROBE_DEFER); | |
412 | ||
413 | mutex_lock(&icc_lock); | |
414 | ||
415 | src = node_find(src_id); | |
416 | if (!src) | |
417 | goto out; | |
418 | ||
419 | dst = node_find(dst_id); | |
420 | if (!dst) | |
421 | goto out; | |
422 | ||
423 | path = path_find(dev, src, dst); | |
424 | if (IS_ERR(path)) | |
425 | dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); | |
426 | ||
427 | out: | |
428 | mutex_unlock(&icc_lock); | |
429 | return path; | |
430 | } | |
431 | EXPORT_SYMBOL_GPL(icc_get); | |
432 | ||
433 | /** | |
434 | * icc_put() - release the reference to the icc_path | |
435 | * @path: interconnect path | |
436 | * | |
437 | * Use this function to release the constraints on a path when the path is | |
438 | * no longer needed. The constraints will be re-aggregated. | |
439 | */ | |
440 | void icc_put(struct icc_path *path) | |
441 | { | |
442 | struct icc_node *node; | |
443 | size_t i; | |
444 | int ret; | |
445 | ||
446 | if (!path || WARN_ON(IS_ERR(path))) | |
447 | return; | |
448 | ||
449 | ret = icc_set_bw(path, 0, 0); | |
450 | if (ret) | |
451 | pr_err("%s: error (%d)\n", __func__, ret); | |
452 | ||
453 | mutex_lock(&icc_lock); | |
454 | for (i = 0; i < path->num_nodes; i++) { | |
455 | node = path->reqs[i].node; | |
456 | hlist_del(&path->reqs[i].req_node); | |
457 | if (!WARN_ON(!node->provider->users)) | |
458 | node->provider->users--; | |
459 | } | |
460 | mutex_unlock(&icc_lock); | |
461 | ||
462 | kfree(path); | |
463 | } | |
464 | EXPORT_SYMBOL_GPL(icc_put); | |
465 | ||
466 | static struct icc_node *icc_node_create_nolock(int id) | |
467 | { | |
468 | struct icc_node *node; | |
469 | ||
470 | /* check if node already exists */ | |
471 | node = node_find(id); | |
472 | if (node) | |
473 | return node; | |
474 | ||
475 | node = kzalloc(sizeof(*node), GFP_KERNEL); | |
476 | if (!node) | |
477 | return ERR_PTR(-ENOMEM); | |
478 | ||
479 | id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL); | |
480 | if (id < 0) { | |
481 | WARN(1, "%s: couldn't get idr\n", __func__); | |
482 | kfree(node); | |
483 | return ERR_PTR(id); | |
484 | } | |
485 | ||
486 | node->id = id; | |
487 | ||
488 | return node; | |
489 | } | |
490 | ||
491 | /** | |
492 | * icc_node_create() - create a node | |
493 | * @id: node id | |
494 | * | |
495 | * Return: icc_node pointer on success, or ERR_PTR() on error | |
496 | */ | |
497 | struct icc_node *icc_node_create(int id) | |
498 | { | |
499 | struct icc_node *node; | |
500 | ||
501 | mutex_lock(&icc_lock); | |
502 | ||
503 | node = icc_node_create_nolock(id); | |
504 | ||
505 | mutex_unlock(&icc_lock); | |
506 | ||
507 | return node; | |
508 | } | |
509 | EXPORT_SYMBOL_GPL(icc_node_create); | |
510 | ||
511 | /** | |
512 | * icc_node_destroy() - destroy a node | |
513 | * @id: node id | |
514 | */ | |
515 | void icc_node_destroy(int id) | |
516 | { | |
517 | struct icc_node *node; | |
518 | ||
519 | mutex_lock(&icc_lock); | |
520 | ||
521 | node = node_find(id); | |
522 | if (node) { | |
523 | idr_remove(&icc_idr, node->id); | |
524 | WARN_ON(!hlist_empty(&node->req_list)); | |
525 | } | |
526 | ||
527 | mutex_unlock(&icc_lock); | |
528 | ||
529 | kfree(node); | |
530 | } | |
531 | EXPORT_SYMBOL_GPL(icc_node_destroy); | |
532 | ||
533 | /** | |
534 | * icc_link_create() - create a link between two nodes | |
535 | * @node: source node id | |
536 | * @dst_id: destination node id | |
537 | * | |
538 | * Create a link between two nodes. The nodes might belong to different | |
539 | * interconnect providers and the @dst_id node might not exist (if the | |
540 | * provider driver has not probed yet). So just create the @dst_id node | |
541 | * and when the actual provider driver is probed, the rest of the node | |
542 | * data is filled. | |
543 | * | |
544 | * Return: 0 on success, or an error code otherwise | |
545 | */ | |
546 | int icc_link_create(struct icc_node *node, const int dst_id) | |
547 | { | |
548 | struct icc_node *dst; | |
549 | struct icc_node **new; | |
550 | int ret = 0; | |
551 | ||
552 | if (!node->provider) | |
553 | return -EINVAL; | |
554 | ||
555 | mutex_lock(&icc_lock); | |
556 | ||
557 | dst = node_find(dst_id); | |
558 | if (!dst) { | |
559 | dst = icc_node_create_nolock(dst_id); | |
560 | ||
561 | if (IS_ERR(dst)) { | |
562 | ret = PTR_ERR(dst); | |
563 | goto out; | |
564 | } | |
565 | } | |
566 | ||
567 | new = krealloc(node->links, | |
568 | (node->num_links + 1) * sizeof(*node->links), | |
569 | GFP_KERNEL); | |
570 | if (!new) { | |
571 | ret = -ENOMEM; | |
572 | goto out; | |
573 | } | |
574 | ||
575 | node->links = new; | |
576 | node->links[node->num_links++] = dst; | |
577 | ||
578 | out: | |
579 | mutex_unlock(&icc_lock); | |
580 | ||
581 | return ret; | |
582 | } | |
583 | EXPORT_SYMBOL_GPL(icc_link_create); | |
584 | ||
585 | /** | |
586 | * icc_link_destroy() - destroy a link between two nodes | |
587 | * @src: pointer to source node | |
588 | * @dst: pointer to destination node | |
589 | * | |
590 | * Return: 0 on success, or an error code otherwise | |
591 | */ | |
592 | int icc_link_destroy(struct icc_node *src, struct icc_node *dst) | |
593 | { | |
594 | struct icc_node **new; | |
595 | size_t slot; | |
596 | int ret = 0; | |
597 | ||
598 | if (IS_ERR_OR_NULL(src)) | |
599 | return -EINVAL; | |
600 | ||
601 | if (IS_ERR_OR_NULL(dst)) | |
602 | return -EINVAL; | |
603 | ||
604 | mutex_lock(&icc_lock); | |
605 | ||
606 | for (slot = 0; slot < src->num_links; slot++) | |
607 | if (src->links[slot] == dst) | |
608 | break; | |
609 | ||
610 | if (WARN_ON(slot == src->num_links)) { | |
611 | ret = -ENXIO; | |
612 | goto out; | |
613 | } | |
614 | ||
615 | src->links[slot] = src->links[--src->num_links]; | |
616 | ||
617 | new = krealloc(src->links, src->num_links * sizeof(*src->links), | |
618 | GFP_KERNEL); | |
619 | if (new) | |
620 | src->links = new; | |
621 | ||
622 | out: | |
623 | mutex_unlock(&icc_lock); | |
624 | ||
625 | return ret; | |
626 | } | |
627 | EXPORT_SYMBOL_GPL(icc_link_destroy); | |
628 | ||
629 | /** | |
630 | * icc_node_add() - add interconnect node to interconnect provider | |
631 | * @node: pointer to the interconnect node | |
632 | * @provider: pointer to the interconnect provider | |
633 | */ | |
634 | void icc_node_add(struct icc_node *node, struct icc_provider *provider) | |
635 | { | |
636 | mutex_lock(&icc_lock); | |
637 | ||
638 | node->provider = provider; | |
639 | list_add_tail(&node->node_list, &provider->nodes); | |
640 | ||
641 | mutex_unlock(&icc_lock); | |
642 | } | |
643 | EXPORT_SYMBOL_GPL(icc_node_add); | |
644 | ||
645 | /** | |
646 | * icc_node_del() - delete interconnect node from interconnect provider | |
647 | * @node: pointer to the interconnect node | |
648 | */ | |
649 | void icc_node_del(struct icc_node *node) | |
650 | { | |
651 | mutex_lock(&icc_lock); | |
652 | ||
653 | list_del(&node->node_list); | |
654 | ||
655 | mutex_unlock(&icc_lock); | |
656 | } | |
657 | EXPORT_SYMBOL_GPL(icc_node_del); | |
658 | ||
659 | /** | |
660 | * icc_provider_add() - add a new interconnect provider | |
661 | * @provider: the interconnect provider that will be added into topology | |
662 | * | |
663 | * Return: 0 on success, or an error code otherwise | |
664 | */ | |
665 | int icc_provider_add(struct icc_provider *provider) | |
666 | { | |
667 | if (WARN_ON(!provider->set)) | |
668 | return -EINVAL; | |
87e3031b GD |
669 | if (WARN_ON(!provider->xlate)) |
670 | return -EINVAL; | |
11f1ceca GD |
671 | |
672 | mutex_lock(&icc_lock); | |
673 | ||
674 | INIT_LIST_HEAD(&provider->nodes); | |
675 | list_add_tail(&provider->provider_list, &icc_providers); | |
676 | ||
677 | mutex_unlock(&icc_lock); | |
678 | ||
679 | dev_dbg(provider->dev, "interconnect provider added to topology\n"); | |
680 | ||
681 | return 0; | |
682 | } | |
683 | EXPORT_SYMBOL_GPL(icc_provider_add); | |
684 | ||
685 | /** | |
686 | * icc_provider_del() - delete previously added interconnect provider | |
687 | * @provider: the interconnect provider that will be removed from topology | |
688 | * | |
689 | * Return: 0 on success, or an error code otherwise | |
690 | */ | |
691 | int icc_provider_del(struct icc_provider *provider) | |
692 | { | |
693 | mutex_lock(&icc_lock); | |
694 | if (provider->users) { | |
695 | pr_warn("interconnect provider still has %d users\n", | |
696 | provider->users); | |
697 | mutex_unlock(&icc_lock); | |
698 | return -EBUSY; | |
699 | } | |
700 | ||
701 | if (!list_empty(&provider->nodes)) { | |
702 | pr_warn("interconnect provider still has nodes\n"); | |
703 | mutex_unlock(&icc_lock); | |
704 | return -EBUSY; | |
705 | } | |
706 | ||
707 | list_del(&provider->provider_list); | |
708 | mutex_unlock(&icc_lock); | |
709 | ||
710 | return 0; | |
711 | } | |
712 | EXPORT_SYMBOL_GPL(icc_provider_del); | |
713 | ||
714 | MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>"); | |
715 | MODULE_DESCRIPTION("Interconnect Driver Core"); | |
716 | MODULE_LICENSE("GPL v2"); |