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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 | ||
3697ff43 | 9 | #include <linux/debugfs.h> |
11f1ceca GD |
10 | #include <linux/device.h> |
11 | #include <linux/idr.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/interconnect.h> | |
14 | #include <linux/interconnect-provider.h> | |
15 | #include <linux/list.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/mutex.h> | |
18 | #include <linux/slab.h> | |
87e3031b | 19 | #include <linux/of.h> |
11f1ceca GD |
20 | #include <linux/overflow.h> |
21 | ||
22 | static DEFINE_IDR(icc_idr); | |
23 | static LIST_HEAD(icc_providers); | |
24 | static DEFINE_MUTEX(icc_lock); | |
3697ff43 | 25 | static struct dentry *icc_debugfs_dir; |
11f1ceca GD |
26 | |
27 | /** | |
28 | * struct icc_req - constraints that are attached to each node | |
29 | * @req_node: entry in list of requests for the particular @node | |
30 | * @node: the interconnect node to which this constraint applies | |
31 | * @dev: reference to the device that sets the constraints | |
32 | * @avg_bw: an integer describing the average bandwidth in kBps | |
33 | * @peak_bw: an integer describing the peak bandwidth in kBps | |
34 | */ | |
35 | struct icc_req { | |
36 | struct hlist_node req_node; | |
37 | struct icc_node *node; | |
38 | struct device *dev; | |
39 | u32 avg_bw; | |
40 | u32 peak_bw; | |
41 | }; | |
42 | ||
43 | /** | |
44 | * struct icc_path - interconnect path structure | |
45 | * @num_nodes: number of hops (nodes) | |
46 | * @reqs: array of the requests applicable to this path of nodes | |
47 | */ | |
48 | struct icc_path { | |
49 | size_t num_nodes; | |
50 | struct icc_req reqs[]; | |
51 | }; | |
52 | ||
3697ff43 GD |
53 | static void icc_summary_show_one(struct seq_file *s, struct icc_node *n) |
54 | { | |
55 | if (!n) | |
56 | return; | |
57 | ||
58 | seq_printf(s, "%-30s %12u %12u\n", | |
59 | n->name, n->avg_bw, n->peak_bw); | |
60 | } | |
61 | ||
62 | static int icc_summary_show(struct seq_file *s, void *data) | |
63 | { | |
64 | struct icc_provider *provider; | |
65 | ||
66 | seq_puts(s, " node avg peak\n"); | |
67 | seq_puts(s, "--------------------------------------------------------\n"); | |
68 | ||
69 | mutex_lock(&icc_lock); | |
70 | ||
71 | list_for_each_entry(provider, &icc_providers, provider_list) { | |
72 | struct icc_node *n; | |
73 | ||
74 | list_for_each_entry(n, &provider->nodes, node_list) { | |
75 | struct icc_req *r; | |
76 | ||
77 | icc_summary_show_one(s, n); | |
78 | hlist_for_each_entry(r, &n->req_list, req_node) { | |
79 | if (!r->dev) | |
80 | continue; | |
81 | ||
82 | seq_printf(s, " %-26s %12u %12u\n", | |
83 | dev_name(r->dev), r->avg_bw, | |
84 | r->peak_bw); | |
85 | } | |
86 | } | |
87 | } | |
88 | ||
89 | mutex_unlock(&icc_lock); | |
90 | ||
91 | return 0; | |
92 | } | |
83fdb2df | 93 | DEFINE_SHOW_ATTRIBUTE(icc_summary); |
3697ff43 | 94 | |
11f1ceca GD |
95 | static struct icc_node *node_find(const int id) |
96 | { | |
97 | return idr_find(&icc_idr, id); | |
98 | } | |
99 | ||
100 | static struct icc_path *path_init(struct device *dev, struct icc_node *dst, | |
101 | ssize_t num_nodes) | |
102 | { | |
103 | struct icc_node *node = dst; | |
104 | struct icc_path *path; | |
105 | int i; | |
106 | ||
107 | path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL); | |
108 | if (!path) | |
109 | return ERR_PTR(-ENOMEM); | |
110 | ||
111 | path->num_nodes = num_nodes; | |
112 | ||
113 | for (i = num_nodes - 1; i >= 0; i--) { | |
114 | node->provider->users++; | |
115 | hlist_add_head(&path->reqs[i].req_node, &node->req_list); | |
116 | path->reqs[i].node = node; | |
117 | path->reqs[i].dev = dev; | |
118 | /* reference to previous node was saved during path traversal */ | |
119 | node = node->reverse; | |
120 | } | |
121 | ||
122 | return path; | |
123 | } | |
124 | ||
125 | static struct icc_path *path_find(struct device *dev, struct icc_node *src, | |
126 | struct icc_node *dst) | |
127 | { | |
128 | struct icc_path *path = ERR_PTR(-EPROBE_DEFER); | |
129 | struct icc_node *n, *node = NULL; | |
130 | struct list_head traverse_list; | |
131 | struct list_head edge_list; | |
132 | struct list_head visited_list; | |
133 | size_t i, depth = 1; | |
134 | bool found = false; | |
135 | ||
136 | INIT_LIST_HEAD(&traverse_list); | |
137 | INIT_LIST_HEAD(&edge_list); | |
138 | INIT_LIST_HEAD(&visited_list); | |
139 | ||
140 | list_add(&src->search_list, &traverse_list); | |
141 | src->reverse = NULL; | |
142 | ||
143 | do { | |
144 | list_for_each_entry_safe(node, n, &traverse_list, search_list) { | |
145 | if (node == dst) { | |
146 | found = true; | |
147 | list_splice_init(&edge_list, &visited_list); | |
148 | list_splice_init(&traverse_list, &visited_list); | |
149 | break; | |
150 | } | |
151 | for (i = 0; i < node->num_links; i++) { | |
152 | struct icc_node *tmp = node->links[i]; | |
153 | ||
154 | if (!tmp) { | |
155 | path = ERR_PTR(-ENOENT); | |
156 | goto out; | |
157 | } | |
158 | ||
159 | if (tmp->is_traversed) | |
160 | continue; | |
161 | ||
162 | tmp->is_traversed = true; | |
163 | tmp->reverse = node; | |
164 | list_add_tail(&tmp->search_list, &edge_list); | |
165 | } | |
166 | } | |
167 | ||
168 | if (found) | |
169 | break; | |
170 | ||
171 | list_splice_init(&traverse_list, &visited_list); | |
172 | list_splice_init(&edge_list, &traverse_list); | |
173 | ||
174 | /* count the hops including the source */ | |
175 | depth++; | |
176 | ||
177 | } while (!list_empty(&traverse_list)); | |
178 | ||
179 | out: | |
180 | ||
181 | /* reset the traversed state */ | |
182 | list_for_each_entry_reverse(n, &visited_list, search_list) | |
183 | n->is_traversed = false; | |
184 | ||
185 | if (found) | |
186 | path = path_init(dev, dst, depth); | |
187 | ||
188 | return path; | |
189 | } | |
190 | ||
191 | /* | |
192 | * We want the path to honor all bandwidth requests, so the average and peak | |
193 | * bandwidth requirements from each consumer are aggregated at each node. | |
194 | * The aggregation is platform specific, so each platform can customize it by | |
195 | * implementing its own aggregate() function. | |
196 | */ | |
197 | ||
198 | static int aggregate_requests(struct icc_node *node) | |
199 | { | |
200 | struct icc_provider *p = node->provider; | |
201 | struct icc_req *r; | |
202 | ||
203 | node->avg_bw = 0; | |
204 | node->peak_bw = 0; | |
205 | ||
206 | hlist_for_each_entry(r, &node->req_list, req_node) | |
207 | p->aggregate(node, r->avg_bw, r->peak_bw, | |
208 | &node->avg_bw, &node->peak_bw); | |
209 | ||
210 | return 0; | |
211 | } | |
212 | ||
213 | static int apply_constraints(struct icc_path *path) | |
214 | { | |
215 | struct icc_node *next, *prev = NULL; | |
216 | int ret = -EINVAL; | |
217 | int i; | |
218 | ||
219 | for (i = 0; i < path->num_nodes; i++) { | |
220 | next = path->reqs[i].node; | |
221 | ||
222 | /* | |
223 | * Both endpoints should be valid master-slave pairs of the | |
224 | * same interconnect provider that will be configured. | |
225 | */ | |
226 | if (!prev || next->provider != prev->provider) { | |
227 | prev = next; | |
228 | continue; | |
229 | } | |
230 | ||
231 | /* set the constraints */ | |
232 | ret = next->provider->set(prev, next); | |
233 | if (ret) | |
234 | goto out; | |
235 | ||
236 | prev = next; | |
237 | } | |
238 | out: | |
239 | return ret; | |
240 | } | |
241 | ||
87e3031b GD |
242 | /* of_icc_xlate_onecell() - Translate function using a single index. |
243 | * @spec: OF phandle args to map into an interconnect node. | |
244 | * @data: private data (pointer to struct icc_onecell_data) | |
245 | * | |
246 | * This is a generic translate function that can be used to model simple | |
247 | * interconnect providers that have one device tree node and provide | |
248 | * multiple interconnect nodes. A single cell is used as an index into | |
249 | * an array of icc nodes specified in the icc_onecell_data struct when | |
250 | * registering the provider. | |
251 | */ | |
252 | struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec, | |
253 | void *data) | |
254 | { | |
255 | struct icc_onecell_data *icc_data = data; | |
256 | unsigned int idx = spec->args[0]; | |
257 | ||
258 | if (idx >= icc_data->num_nodes) { | |
259 | pr_err("%s: invalid index %u\n", __func__, idx); | |
260 | return ERR_PTR(-EINVAL); | |
261 | } | |
262 | ||
263 | return icc_data->nodes[idx]; | |
264 | } | |
265 | EXPORT_SYMBOL_GPL(of_icc_xlate_onecell); | |
266 | ||
267 | /** | |
268 | * of_icc_get_from_provider() - Look-up interconnect node | |
269 | * @spec: OF phandle args to use for look-up | |
270 | * | |
271 | * Looks for interconnect provider under the node specified by @spec and if | |
272 | * found, uses xlate function of the provider to map phandle args to node. | |
273 | * | |
274 | * Returns a valid pointer to struct icc_node on success or ERR_PTR() | |
275 | * on failure. | |
276 | */ | |
277 | static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec) | |
278 | { | |
279 | struct icc_node *node = ERR_PTR(-EPROBE_DEFER); | |
280 | struct icc_provider *provider; | |
281 | ||
282 | if (!spec || spec->args_count != 1) | |
283 | return ERR_PTR(-EINVAL); | |
284 | ||
285 | mutex_lock(&icc_lock); | |
286 | list_for_each_entry(provider, &icc_providers, provider_list) { | |
287 | if (provider->dev->of_node == spec->np) | |
288 | node = provider->xlate(spec, provider->data); | |
289 | if (!IS_ERR(node)) | |
290 | break; | |
291 | } | |
292 | mutex_unlock(&icc_lock); | |
293 | ||
294 | return node; | |
295 | } | |
296 | ||
297 | /** | |
298 | * of_icc_get() - get a path handle from a DT node based on name | |
299 | * @dev: device pointer for the consumer device | |
300 | * @name: interconnect path name | |
301 | * | |
302 | * This function will search for a path between two endpoints and return an | |
303 | * icc_path handle on success. Use icc_put() to release constraints when they | |
304 | * are not needed anymore. | |
305 | * If the interconnect API is disabled, NULL is returned and the consumer | |
306 | * drivers will still build. Drivers are free to handle this specifically, | |
307 | * but they don't have to. | |
308 | * | |
309 | * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned | |
310 | * when the API is disabled or the "interconnects" DT property is missing. | |
311 | */ | |
312 | struct icc_path *of_icc_get(struct device *dev, const char *name) | |
313 | { | |
314 | struct icc_path *path = ERR_PTR(-EPROBE_DEFER); | |
315 | struct icc_node *src_node, *dst_node; | |
316 | struct device_node *np = NULL; | |
317 | struct of_phandle_args src_args, dst_args; | |
318 | int idx = 0; | |
319 | int ret; | |
320 | ||
321 | if (!dev || !dev->of_node) | |
322 | return ERR_PTR(-ENODEV); | |
323 | ||
324 | np = dev->of_node; | |
325 | ||
326 | /* | |
327 | * When the consumer DT node do not have "interconnects" property | |
328 | * return a NULL path to skip setting constraints. | |
329 | */ | |
330 | if (!of_find_property(np, "interconnects", NULL)) | |
331 | return NULL; | |
332 | ||
333 | /* | |
334 | * We use a combination of phandle and specifier for endpoint. For now | |
335 | * lets support only global ids and extend this in the future if needed | |
336 | * without breaking DT compatibility. | |
337 | */ | |
338 | if (name) { | |
339 | idx = of_property_match_string(np, "interconnect-names", name); | |
340 | if (idx < 0) | |
341 | return ERR_PTR(idx); | |
342 | } | |
343 | ||
344 | ret = of_parse_phandle_with_args(np, "interconnects", | |
345 | "#interconnect-cells", idx * 2, | |
346 | &src_args); | |
347 | if (ret) | |
348 | return ERR_PTR(ret); | |
349 | ||
350 | of_node_put(src_args.np); | |
351 | ||
352 | ret = of_parse_phandle_with_args(np, "interconnects", | |
353 | "#interconnect-cells", idx * 2 + 1, | |
354 | &dst_args); | |
355 | if (ret) | |
356 | return ERR_PTR(ret); | |
357 | ||
358 | of_node_put(dst_args.np); | |
359 | ||
360 | src_node = of_icc_get_from_provider(&src_args); | |
361 | ||
362 | if (IS_ERR(src_node)) { | |
363 | if (PTR_ERR(src_node) != -EPROBE_DEFER) | |
364 | dev_err(dev, "error finding src node: %ld\n", | |
365 | PTR_ERR(src_node)); | |
366 | return ERR_CAST(src_node); | |
367 | } | |
368 | ||
369 | dst_node = of_icc_get_from_provider(&dst_args); | |
370 | ||
371 | if (IS_ERR(dst_node)) { | |
372 | if (PTR_ERR(dst_node) != -EPROBE_DEFER) | |
373 | dev_err(dev, "error finding dst node: %ld\n", | |
374 | PTR_ERR(dst_node)); | |
375 | return ERR_CAST(dst_node); | |
376 | } | |
377 | ||
378 | mutex_lock(&icc_lock); | |
379 | path = path_find(dev, src_node, dst_node); | |
380 | if (IS_ERR(path)) | |
381 | dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); | |
382 | mutex_unlock(&icc_lock); | |
383 | ||
384 | return path; | |
385 | } | |
386 | EXPORT_SYMBOL_GPL(of_icc_get); | |
387 | ||
11f1ceca GD |
388 | /** |
389 | * icc_set_bw() - set bandwidth constraints on an interconnect path | |
390 | * @path: reference to the path returned by icc_get() | |
391 | * @avg_bw: average bandwidth in kilobytes per second | |
392 | * @peak_bw: peak bandwidth in kilobytes per second | |
393 | * | |
394 | * This function is used by an interconnect consumer to express its own needs | |
395 | * in terms of bandwidth for a previously requested path between two endpoints. | |
396 | * The requests are aggregated and each node is updated accordingly. The entire | |
397 | * path is locked by a mutex to ensure that the set() is completed. | |
398 | * The @path can be NULL when the "interconnects" DT properties is missing, | |
399 | * which will mean that no constraints will be set. | |
400 | * | |
401 | * Returns 0 on success, or an appropriate error code otherwise. | |
402 | */ | |
403 | int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw) | |
404 | { | |
405 | struct icc_node *node; | |
dce6d406 | 406 | u32 old_avg, old_peak; |
11f1ceca GD |
407 | size_t i; |
408 | int ret; | |
409 | ||
dce6d406 | 410 | if (!path || !path->num_nodes) |
11f1ceca GD |
411 | return 0; |
412 | ||
413 | mutex_lock(&icc_lock); | |
414 | ||
dce6d406 GD |
415 | old_avg = path->reqs[0].avg_bw; |
416 | old_peak = path->reqs[0].peak_bw; | |
417 | ||
11f1ceca GD |
418 | for (i = 0; i < path->num_nodes; i++) { |
419 | node = path->reqs[i].node; | |
420 | ||
421 | /* update the consumer request for this path */ | |
422 | path->reqs[i].avg_bw = avg_bw; | |
423 | path->reqs[i].peak_bw = peak_bw; | |
424 | ||
425 | /* aggregate requests for this node */ | |
426 | aggregate_requests(node); | |
427 | } | |
428 | ||
429 | ret = apply_constraints(path); | |
dce6d406 | 430 | if (ret) { |
11f1ceca GD |
431 | pr_debug("interconnect: error applying constraints (%d)\n", |
432 | ret); | |
433 | ||
dce6d406 GD |
434 | for (i = 0; i < path->num_nodes; i++) { |
435 | node = path->reqs[i].node; | |
436 | path->reqs[i].avg_bw = old_avg; | |
437 | path->reqs[i].peak_bw = old_peak; | |
438 | aggregate_requests(node); | |
439 | } | |
440 | apply_constraints(path); | |
441 | } | |
442 | ||
11f1ceca GD |
443 | mutex_unlock(&icc_lock); |
444 | ||
445 | return ret; | |
446 | } | |
447 | EXPORT_SYMBOL_GPL(icc_set_bw); | |
448 | ||
449 | /** | |
450 | * icc_get() - return a handle for path between two endpoints | |
451 | * @dev: the device requesting the path | |
452 | * @src_id: source device port id | |
453 | * @dst_id: destination device port id | |
454 | * | |
455 | * This function will search for a path between two endpoints and return an | |
456 | * icc_path handle on success. Use icc_put() to release | |
457 | * constraints when they are not needed anymore. | |
458 | * If the interconnect API is disabled, NULL is returned and the consumer | |
459 | * drivers will still build. Drivers are free to handle this specifically, | |
460 | * but they don't have to. | |
461 | * | |
462 | * Return: icc_path pointer on success, ERR_PTR() on error or NULL if the | |
463 | * interconnect API is disabled. | |
464 | */ | |
465 | struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id) | |
466 | { | |
467 | struct icc_node *src, *dst; | |
468 | struct icc_path *path = ERR_PTR(-EPROBE_DEFER); | |
469 | ||
470 | mutex_lock(&icc_lock); | |
471 | ||
472 | src = node_find(src_id); | |
473 | if (!src) | |
474 | goto out; | |
475 | ||
476 | dst = node_find(dst_id); | |
477 | if (!dst) | |
478 | goto out; | |
479 | ||
480 | path = path_find(dev, src, dst); | |
481 | if (IS_ERR(path)) | |
482 | dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); | |
483 | ||
484 | out: | |
485 | mutex_unlock(&icc_lock); | |
486 | return path; | |
487 | } | |
488 | EXPORT_SYMBOL_GPL(icc_get); | |
489 | ||
490 | /** | |
491 | * icc_put() - release the reference to the icc_path | |
492 | * @path: interconnect path | |
493 | * | |
494 | * Use this function to release the constraints on a path when the path is | |
495 | * no longer needed. The constraints will be re-aggregated. | |
496 | */ | |
497 | void icc_put(struct icc_path *path) | |
498 | { | |
499 | struct icc_node *node; | |
500 | size_t i; | |
501 | int ret; | |
502 | ||
503 | if (!path || WARN_ON(IS_ERR(path))) | |
504 | return; | |
505 | ||
506 | ret = icc_set_bw(path, 0, 0); | |
507 | if (ret) | |
508 | pr_err("%s: error (%d)\n", __func__, ret); | |
509 | ||
510 | mutex_lock(&icc_lock); | |
511 | for (i = 0; i < path->num_nodes; i++) { | |
512 | node = path->reqs[i].node; | |
513 | hlist_del(&path->reqs[i].req_node); | |
514 | if (!WARN_ON(!node->provider->users)) | |
515 | node->provider->users--; | |
516 | } | |
517 | mutex_unlock(&icc_lock); | |
518 | ||
519 | kfree(path); | |
520 | } | |
521 | EXPORT_SYMBOL_GPL(icc_put); | |
522 | ||
523 | static struct icc_node *icc_node_create_nolock(int id) | |
524 | { | |
525 | struct icc_node *node; | |
526 | ||
527 | /* check if node already exists */ | |
528 | node = node_find(id); | |
529 | if (node) | |
530 | return node; | |
531 | ||
532 | node = kzalloc(sizeof(*node), GFP_KERNEL); | |
533 | if (!node) | |
534 | return ERR_PTR(-ENOMEM); | |
535 | ||
536 | id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL); | |
537 | if (id < 0) { | |
538 | WARN(1, "%s: couldn't get idr\n", __func__); | |
539 | kfree(node); | |
540 | return ERR_PTR(id); | |
541 | } | |
542 | ||
543 | node->id = id; | |
544 | ||
545 | return node; | |
546 | } | |
547 | ||
548 | /** | |
549 | * icc_node_create() - create a node | |
550 | * @id: node id | |
551 | * | |
552 | * Return: icc_node pointer on success, or ERR_PTR() on error | |
553 | */ | |
554 | struct icc_node *icc_node_create(int id) | |
555 | { | |
556 | struct icc_node *node; | |
557 | ||
558 | mutex_lock(&icc_lock); | |
559 | ||
560 | node = icc_node_create_nolock(id); | |
561 | ||
562 | mutex_unlock(&icc_lock); | |
563 | ||
564 | return node; | |
565 | } | |
566 | EXPORT_SYMBOL_GPL(icc_node_create); | |
567 | ||
568 | /** | |
569 | * icc_node_destroy() - destroy a node | |
570 | * @id: node id | |
571 | */ | |
572 | void icc_node_destroy(int id) | |
573 | { | |
574 | struct icc_node *node; | |
575 | ||
576 | mutex_lock(&icc_lock); | |
577 | ||
578 | node = node_find(id); | |
579 | if (node) { | |
580 | idr_remove(&icc_idr, node->id); | |
581 | WARN_ON(!hlist_empty(&node->req_list)); | |
582 | } | |
583 | ||
584 | mutex_unlock(&icc_lock); | |
585 | ||
586 | kfree(node); | |
587 | } | |
588 | EXPORT_SYMBOL_GPL(icc_node_destroy); | |
589 | ||
590 | /** | |
591 | * icc_link_create() - create a link between two nodes | |
592 | * @node: source node id | |
593 | * @dst_id: destination node id | |
594 | * | |
595 | * Create a link between two nodes. The nodes might belong to different | |
596 | * interconnect providers and the @dst_id node might not exist (if the | |
597 | * provider driver has not probed yet). So just create the @dst_id node | |
598 | * and when the actual provider driver is probed, the rest of the node | |
599 | * data is filled. | |
600 | * | |
601 | * Return: 0 on success, or an error code otherwise | |
602 | */ | |
603 | int icc_link_create(struct icc_node *node, const int dst_id) | |
604 | { | |
605 | struct icc_node *dst; | |
606 | struct icc_node **new; | |
607 | int ret = 0; | |
608 | ||
609 | if (!node->provider) | |
610 | return -EINVAL; | |
611 | ||
612 | mutex_lock(&icc_lock); | |
613 | ||
614 | dst = node_find(dst_id); | |
615 | if (!dst) { | |
616 | dst = icc_node_create_nolock(dst_id); | |
617 | ||
618 | if (IS_ERR(dst)) { | |
619 | ret = PTR_ERR(dst); | |
620 | goto out; | |
621 | } | |
622 | } | |
623 | ||
624 | new = krealloc(node->links, | |
625 | (node->num_links + 1) * sizeof(*node->links), | |
626 | GFP_KERNEL); | |
627 | if (!new) { | |
628 | ret = -ENOMEM; | |
629 | goto out; | |
630 | } | |
631 | ||
632 | node->links = new; | |
633 | node->links[node->num_links++] = dst; | |
634 | ||
635 | out: | |
636 | mutex_unlock(&icc_lock); | |
637 | ||
638 | return ret; | |
639 | } | |
640 | EXPORT_SYMBOL_GPL(icc_link_create); | |
641 | ||
642 | /** | |
643 | * icc_link_destroy() - destroy a link between two nodes | |
644 | * @src: pointer to source node | |
645 | * @dst: pointer to destination node | |
646 | * | |
647 | * Return: 0 on success, or an error code otherwise | |
648 | */ | |
649 | int icc_link_destroy(struct icc_node *src, struct icc_node *dst) | |
650 | { | |
651 | struct icc_node **new; | |
652 | size_t slot; | |
653 | int ret = 0; | |
654 | ||
655 | if (IS_ERR_OR_NULL(src)) | |
656 | return -EINVAL; | |
657 | ||
658 | if (IS_ERR_OR_NULL(dst)) | |
659 | return -EINVAL; | |
660 | ||
661 | mutex_lock(&icc_lock); | |
662 | ||
663 | for (slot = 0; slot < src->num_links; slot++) | |
664 | if (src->links[slot] == dst) | |
665 | break; | |
666 | ||
667 | if (WARN_ON(slot == src->num_links)) { | |
668 | ret = -ENXIO; | |
669 | goto out; | |
670 | } | |
671 | ||
672 | src->links[slot] = src->links[--src->num_links]; | |
673 | ||
674 | new = krealloc(src->links, src->num_links * sizeof(*src->links), | |
675 | GFP_KERNEL); | |
676 | if (new) | |
677 | src->links = new; | |
678 | ||
679 | out: | |
680 | mutex_unlock(&icc_lock); | |
681 | ||
682 | return ret; | |
683 | } | |
684 | EXPORT_SYMBOL_GPL(icc_link_destroy); | |
685 | ||
686 | /** | |
687 | * icc_node_add() - add interconnect node to interconnect provider | |
688 | * @node: pointer to the interconnect node | |
689 | * @provider: pointer to the interconnect provider | |
690 | */ | |
691 | void icc_node_add(struct icc_node *node, struct icc_provider *provider) | |
692 | { | |
693 | mutex_lock(&icc_lock); | |
694 | ||
695 | node->provider = provider; | |
696 | list_add_tail(&node->node_list, &provider->nodes); | |
697 | ||
698 | mutex_unlock(&icc_lock); | |
699 | } | |
700 | EXPORT_SYMBOL_GPL(icc_node_add); | |
701 | ||
702 | /** | |
703 | * icc_node_del() - delete interconnect node from interconnect provider | |
704 | * @node: pointer to the interconnect node | |
705 | */ | |
706 | void icc_node_del(struct icc_node *node) | |
707 | { | |
708 | mutex_lock(&icc_lock); | |
709 | ||
710 | list_del(&node->node_list); | |
711 | ||
712 | mutex_unlock(&icc_lock); | |
713 | } | |
714 | EXPORT_SYMBOL_GPL(icc_node_del); | |
715 | ||
716 | /** | |
717 | * icc_provider_add() - add a new interconnect provider | |
718 | * @provider: the interconnect provider that will be added into topology | |
719 | * | |
720 | * Return: 0 on success, or an error code otherwise | |
721 | */ | |
722 | int icc_provider_add(struct icc_provider *provider) | |
723 | { | |
724 | if (WARN_ON(!provider->set)) | |
725 | return -EINVAL; | |
87e3031b GD |
726 | if (WARN_ON(!provider->xlate)) |
727 | return -EINVAL; | |
11f1ceca GD |
728 | |
729 | mutex_lock(&icc_lock); | |
730 | ||
731 | INIT_LIST_HEAD(&provider->nodes); | |
732 | list_add_tail(&provider->provider_list, &icc_providers); | |
733 | ||
734 | mutex_unlock(&icc_lock); | |
735 | ||
736 | dev_dbg(provider->dev, "interconnect provider added to topology\n"); | |
737 | ||
738 | return 0; | |
739 | } | |
740 | EXPORT_SYMBOL_GPL(icc_provider_add); | |
741 | ||
742 | /** | |
743 | * icc_provider_del() - delete previously added interconnect provider | |
744 | * @provider: the interconnect provider that will be removed from topology | |
745 | * | |
746 | * Return: 0 on success, or an error code otherwise | |
747 | */ | |
748 | int icc_provider_del(struct icc_provider *provider) | |
749 | { | |
750 | mutex_lock(&icc_lock); | |
751 | if (provider->users) { | |
752 | pr_warn("interconnect provider still has %d users\n", | |
753 | provider->users); | |
754 | mutex_unlock(&icc_lock); | |
755 | return -EBUSY; | |
756 | } | |
757 | ||
758 | if (!list_empty(&provider->nodes)) { | |
759 | pr_warn("interconnect provider still has nodes\n"); | |
760 | mutex_unlock(&icc_lock); | |
761 | return -EBUSY; | |
762 | } | |
763 | ||
764 | list_del(&provider->provider_list); | |
765 | mutex_unlock(&icc_lock); | |
766 | ||
767 | return 0; | |
768 | } | |
769 | EXPORT_SYMBOL_GPL(icc_provider_del); | |
770 | ||
3697ff43 GD |
771 | static int __init icc_init(void) |
772 | { | |
773 | icc_debugfs_dir = debugfs_create_dir("interconnect", NULL); | |
774 | debugfs_create_file("interconnect_summary", 0444, | |
775 | icc_debugfs_dir, NULL, &icc_summary_fops); | |
776 | return 0; | |
777 | } | |
778 | ||
779 | static void __exit icc_exit(void) | |
780 | { | |
781 | debugfs_remove_recursive(icc_debugfs_dir); | |
782 | } | |
783 | module_init(icc_init); | |
784 | module_exit(icc_exit); | |
785 | ||
11f1ceca GD |
786 | MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>"); |
787 | MODULE_DESCRIPTION("Interconnect Driver Core"); | |
788 | MODULE_LICENSE("GPL v2"); |