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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 | |
127ab2cc | 32 | * @tag: path tag (optional) |
11f1ceca GD |
33 | * @avg_bw: an integer describing the average bandwidth in kBps |
34 | * @peak_bw: an integer describing the peak bandwidth in kBps | |
35 | */ | |
36 | struct icc_req { | |
37 | struct hlist_node req_node; | |
38 | struct icc_node *node; | |
39 | struct device *dev; | |
127ab2cc | 40 | u32 tag; |
11f1ceca GD |
41 | u32 avg_bw; |
42 | u32 peak_bw; | |
43 | }; | |
44 | ||
45 | /** | |
46 | * struct icc_path - interconnect path structure | |
47 | * @num_nodes: number of hops (nodes) | |
48 | * @reqs: array of the requests applicable to this path of nodes | |
49 | */ | |
50 | struct icc_path { | |
51 | size_t num_nodes; | |
52 | struct icc_req reqs[]; | |
53 | }; | |
54 | ||
3697ff43 GD |
55 | static void icc_summary_show_one(struct seq_file *s, struct icc_node *n) |
56 | { | |
57 | if (!n) | |
58 | return; | |
59 | ||
60 | seq_printf(s, "%-30s %12u %12u\n", | |
61 | n->name, n->avg_bw, n->peak_bw); | |
62 | } | |
63 | ||
64 | static int icc_summary_show(struct seq_file *s, void *data) | |
65 | { | |
66 | struct icc_provider *provider; | |
67 | ||
68 | seq_puts(s, " node avg peak\n"); | |
69 | seq_puts(s, "--------------------------------------------------------\n"); | |
70 | ||
71 | mutex_lock(&icc_lock); | |
72 | ||
73 | list_for_each_entry(provider, &icc_providers, provider_list) { | |
74 | struct icc_node *n; | |
75 | ||
76 | list_for_each_entry(n, &provider->nodes, node_list) { | |
77 | struct icc_req *r; | |
78 | ||
79 | icc_summary_show_one(s, n); | |
80 | hlist_for_each_entry(r, &n->req_list, req_node) { | |
81 | if (!r->dev) | |
82 | continue; | |
83 | ||
84 | seq_printf(s, " %-26s %12u %12u\n", | |
85 | dev_name(r->dev), r->avg_bw, | |
86 | r->peak_bw); | |
87 | } | |
88 | } | |
89 | } | |
90 | ||
91 | mutex_unlock(&icc_lock); | |
92 | ||
93 | return 0; | |
94 | } | |
83fdb2df | 95 | DEFINE_SHOW_ATTRIBUTE(icc_summary); |
3697ff43 | 96 | |
11f1ceca GD |
97 | static struct icc_node *node_find(const int id) |
98 | { | |
99 | return idr_find(&icc_idr, id); | |
100 | } | |
101 | ||
102 | static struct icc_path *path_init(struct device *dev, struct icc_node *dst, | |
103 | ssize_t num_nodes) | |
104 | { | |
105 | struct icc_node *node = dst; | |
106 | struct icc_path *path; | |
107 | int i; | |
108 | ||
109 | path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL); | |
110 | if (!path) | |
111 | return ERR_PTR(-ENOMEM); | |
112 | ||
113 | path->num_nodes = num_nodes; | |
114 | ||
115 | for (i = num_nodes - 1; i >= 0; i--) { | |
116 | node->provider->users++; | |
117 | hlist_add_head(&path->reqs[i].req_node, &node->req_list); | |
118 | path->reqs[i].node = node; | |
119 | path->reqs[i].dev = dev; | |
120 | /* reference to previous node was saved during path traversal */ | |
121 | node = node->reverse; | |
122 | } | |
123 | ||
124 | return path; | |
125 | } | |
126 | ||
127 | static struct icc_path *path_find(struct device *dev, struct icc_node *src, | |
128 | struct icc_node *dst) | |
129 | { | |
130 | struct icc_path *path = ERR_PTR(-EPROBE_DEFER); | |
131 | struct icc_node *n, *node = NULL; | |
132 | struct list_head traverse_list; | |
133 | struct list_head edge_list; | |
134 | struct list_head visited_list; | |
135 | size_t i, depth = 1; | |
136 | bool found = false; | |
137 | ||
138 | INIT_LIST_HEAD(&traverse_list); | |
139 | INIT_LIST_HEAD(&edge_list); | |
140 | INIT_LIST_HEAD(&visited_list); | |
141 | ||
142 | list_add(&src->search_list, &traverse_list); | |
143 | src->reverse = NULL; | |
144 | ||
145 | do { | |
146 | list_for_each_entry_safe(node, n, &traverse_list, search_list) { | |
147 | if (node == dst) { | |
148 | found = true; | |
149 | list_splice_init(&edge_list, &visited_list); | |
150 | list_splice_init(&traverse_list, &visited_list); | |
151 | break; | |
152 | } | |
153 | for (i = 0; i < node->num_links; i++) { | |
154 | struct icc_node *tmp = node->links[i]; | |
155 | ||
156 | if (!tmp) { | |
157 | path = ERR_PTR(-ENOENT); | |
158 | goto out; | |
159 | } | |
160 | ||
161 | if (tmp->is_traversed) | |
162 | continue; | |
163 | ||
164 | tmp->is_traversed = true; | |
165 | tmp->reverse = node; | |
166 | list_add_tail(&tmp->search_list, &edge_list); | |
167 | } | |
168 | } | |
169 | ||
170 | if (found) | |
171 | break; | |
172 | ||
173 | list_splice_init(&traverse_list, &visited_list); | |
174 | list_splice_init(&edge_list, &traverse_list); | |
175 | ||
176 | /* count the hops including the source */ | |
177 | depth++; | |
178 | ||
179 | } while (!list_empty(&traverse_list)); | |
180 | ||
181 | out: | |
182 | ||
183 | /* reset the traversed state */ | |
184 | list_for_each_entry_reverse(n, &visited_list, search_list) | |
185 | n->is_traversed = false; | |
186 | ||
187 | if (found) | |
188 | path = path_init(dev, dst, depth); | |
189 | ||
190 | return path; | |
191 | } | |
192 | ||
193 | /* | |
194 | * We want the path to honor all bandwidth requests, so the average and peak | |
195 | * bandwidth requirements from each consumer are aggregated at each node. | |
196 | * The aggregation is platform specific, so each platform can customize it by | |
197 | * implementing its own aggregate() function. | |
198 | */ | |
199 | ||
200 | static int aggregate_requests(struct icc_node *node) | |
201 | { | |
202 | struct icc_provider *p = node->provider; | |
203 | struct icc_req *r; | |
204 | ||
205 | node->avg_bw = 0; | |
206 | node->peak_bw = 0; | |
207 | ||
cbd5a9c2 GD |
208 | if (p->pre_aggregate) |
209 | p->pre_aggregate(node); | |
210 | ||
11f1ceca | 211 | hlist_for_each_entry(r, &node->req_list, req_node) |
127ab2cc | 212 | p->aggregate(node, r->tag, r->avg_bw, r->peak_bw, |
11f1ceca GD |
213 | &node->avg_bw, &node->peak_bw); |
214 | ||
215 | return 0; | |
216 | } | |
217 | ||
218 | static int apply_constraints(struct icc_path *path) | |
219 | { | |
220 | struct icc_node *next, *prev = NULL; | |
221 | int ret = -EINVAL; | |
222 | int i; | |
223 | ||
224 | for (i = 0; i < path->num_nodes; i++) { | |
225 | next = path->reqs[i].node; | |
226 | ||
227 | /* | |
228 | * Both endpoints should be valid master-slave pairs of the | |
229 | * same interconnect provider that will be configured. | |
230 | */ | |
231 | if (!prev || next->provider != prev->provider) { | |
232 | prev = next; | |
233 | continue; | |
234 | } | |
235 | ||
236 | /* set the constraints */ | |
237 | ret = next->provider->set(prev, next); | |
238 | if (ret) | |
239 | goto out; | |
240 | ||
241 | prev = next; | |
242 | } | |
243 | out: | |
244 | return ret; | |
245 | } | |
246 | ||
87e3031b GD |
247 | /* of_icc_xlate_onecell() - Translate function using a single index. |
248 | * @spec: OF phandle args to map into an interconnect node. | |
249 | * @data: private data (pointer to struct icc_onecell_data) | |
250 | * | |
251 | * This is a generic translate function that can be used to model simple | |
252 | * interconnect providers that have one device tree node and provide | |
253 | * multiple interconnect nodes. A single cell is used as an index into | |
254 | * an array of icc nodes specified in the icc_onecell_data struct when | |
255 | * registering the provider. | |
256 | */ | |
257 | struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec, | |
258 | void *data) | |
259 | { | |
260 | struct icc_onecell_data *icc_data = data; | |
261 | unsigned int idx = spec->args[0]; | |
262 | ||
263 | if (idx >= icc_data->num_nodes) { | |
264 | pr_err("%s: invalid index %u\n", __func__, idx); | |
265 | return ERR_PTR(-EINVAL); | |
266 | } | |
267 | ||
268 | return icc_data->nodes[idx]; | |
269 | } | |
270 | EXPORT_SYMBOL_GPL(of_icc_xlate_onecell); | |
271 | ||
272 | /** | |
273 | * of_icc_get_from_provider() - Look-up interconnect node | |
274 | * @spec: OF phandle args to use for look-up | |
275 | * | |
276 | * Looks for interconnect provider under the node specified by @spec and if | |
277 | * found, uses xlate function of the provider to map phandle args to node. | |
278 | * | |
279 | * Returns a valid pointer to struct icc_node on success or ERR_PTR() | |
280 | * on failure. | |
281 | */ | |
282 | static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec) | |
283 | { | |
284 | struct icc_node *node = ERR_PTR(-EPROBE_DEFER); | |
285 | struct icc_provider *provider; | |
286 | ||
287 | if (!spec || spec->args_count != 1) | |
288 | return ERR_PTR(-EINVAL); | |
289 | ||
290 | mutex_lock(&icc_lock); | |
291 | list_for_each_entry(provider, &icc_providers, provider_list) { | |
292 | if (provider->dev->of_node == spec->np) | |
293 | node = provider->xlate(spec, provider->data); | |
294 | if (!IS_ERR(node)) | |
295 | break; | |
296 | } | |
297 | mutex_unlock(&icc_lock); | |
298 | ||
299 | return node; | |
300 | } | |
301 | ||
302 | /** | |
303 | * of_icc_get() - get a path handle from a DT node based on name | |
304 | * @dev: device pointer for the consumer device | |
305 | * @name: interconnect path name | |
306 | * | |
307 | * This function will search for a path between two endpoints and return an | |
308 | * icc_path handle on success. Use icc_put() to release constraints when they | |
309 | * are not needed anymore. | |
310 | * If the interconnect API is disabled, NULL is returned and the consumer | |
311 | * drivers will still build. Drivers are free to handle this specifically, | |
312 | * but they don't have to. | |
313 | * | |
314 | * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned | |
315 | * when the API is disabled or the "interconnects" DT property is missing. | |
316 | */ | |
317 | struct icc_path *of_icc_get(struct device *dev, const char *name) | |
318 | { | |
319 | struct icc_path *path = ERR_PTR(-EPROBE_DEFER); | |
320 | struct icc_node *src_node, *dst_node; | |
321 | struct device_node *np = NULL; | |
322 | struct of_phandle_args src_args, dst_args; | |
323 | int idx = 0; | |
324 | int ret; | |
325 | ||
326 | if (!dev || !dev->of_node) | |
327 | return ERR_PTR(-ENODEV); | |
328 | ||
329 | np = dev->of_node; | |
330 | ||
331 | /* | |
332 | * When the consumer DT node do not have "interconnects" property | |
333 | * return a NULL path to skip setting constraints. | |
334 | */ | |
335 | if (!of_find_property(np, "interconnects", NULL)) | |
336 | return NULL; | |
337 | ||
338 | /* | |
339 | * We use a combination of phandle and specifier for endpoint. For now | |
340 | * lets support only global ids and extend this in the future if needed | |
341 | * without breaking DT compatibility. | |
342 | */ | |
343 | if (name) { | |
344 | idx = of_property_match_string(np, "interconnect-names", name); | |
345 | if (idx < 0) | |
346 | return ERR_PTR(idx); | |
347 | } | |
348 | ||
349 | ret = of_parse_phandle_with_args(np, "interconnects", | |
350 | "#interconnect-cells", idx * 2, | |
351 | &src_args); | |
352 | if (ret) | |
353 | return ERR_PTR(ret); | |
354 | ||
355 | of_node_put(src_args.np); | |
356 | ||
357 | ret = of_parse_phandle_with_args(np, "interconnects", | |
358 | "#interconnect-cells", idx * 2 + 1, | |
359 | &dst_args); | |
360 | if (ret) | |
361 | return ERR_PTR(ret); | |
362 | ||
363 | of_node_put(dst_args.np); | |
364 | ||
365 | src_node = of_icc_get_from_provider(&src_args); | |
366 | ||
367 | if (IS_ERR(src_node)) { | |
368 | if (PTR_ERR(src_node) != -EPROBE_DEFER) | |
369 | dev_err(dev, "error finding src node: %ld\n", | |
370 | PTR_ERR(src_node)); | |
371 | return ERR_CAST(src_node); | |
372 | } | |
373 | ||
374 | dst_node = of_icc_get_from_provider(&dst_args); | |
375 | ||
376 | if (IS_ERR(dst_node)) { | |
377 | if (PTR_ERR(dst_node) != -EPROBE_DEFER) | |
378 | dev_err(dev, "error finding dst node: %ld\n", | |
379 | PTR_ERR(dst_node)); | |
380 | return ERR_CAST(dst_node); | |
381 | } | |
382 | ||
383 | mutex_lock(&icc_lock); | |
384 | path = path_find(dev, src_node, dst_node); | |
385 | if (IS_ERR(path)) | |
386 | dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); | |
387 | mutex_unlock(&icc_lock); | |
388 | ||
389 | return path; | |
390 | } | |
391 | EXPORT_SYMBOL_GPL(of_icc_get); | |
392 | ||
127ab2cc GD |
393 | /** |
394 | * icc_set_tag() - set an optional tag on a path | |
395 | * @path: the path we want to tag | |
396 | * @tag: the tag value | |
397 | * | |
398 | * This function allows consumers to append a tag to the requests associated | |
399 | * with a path, so that a different aggregation could be done based on this tag. | |
400 | */ | |
401 | void icc_set_tag(struct icc_path *path, u32 tag) | |
402 | { | |
403 | int i; | |
404 | ||
405 | if (!path) | |
406 | return; | |
407 | ||
408 | for (i = 0; i < path->num_nodes; i++) | |
409 | path->reqs[i].tag = tag; | |
410 | } | |
411 | EXPORT_SYMBOL_GPL(icc_set_tag); | |
412 | ||
11f1ceca GD |
413 | /** |
414 | * icc_set_bw() - set bandwidth constraints on an interconnect path | |
415 | * @path: reference to the path returned by icc_get() | |
416 | * @avg_bw: average bandwidth in kilobytes per second | |
417 | * @peak_bw: peak bandwidth in kilobytes per second | |
418 | * | |
419 | * This function is used by an interconnect consumer to express its own needs | |
420 | * in terms of bandwidth for a previously requested path between two endpoints. | |
421 | * The requests are aggregated and each node is updated accordingly. The entire | |
422 | * path is locked by a mutex to ensure that the set() is completed. | |
423 | * The @path can be NULL when the "interconnects" DT properties is missing, | |
424 | * which will mean that no constraints will be set. | |
425 | * | |
426 | * Returns 0 on success, or an appropriate error code otherwise. | |
427 | */ | |
428 | int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw) | |
429 | { | |
430 | struct icc_node *node; | |
dce6d406 | 431 | u32 old_avg, old_peak; |
11f1ceca GD |
432 | size_t i; |
433 | int ret; | |
434 | ||
dce6d406 | 435 | if (!path || !path->num_nodes) |
11f1ceca GD |
436 | return 0; |
437 | ||
438 | mutex_lock(&icc_lock); | |
439 | ||
dce6d406 GD |
440 | old_avg = path->reqs[0].avg_bw; |
441 | old_peak = path->reqs[0].peak_bw; | |
442 | ||
11f1ceca GD |
443 | for (i = 0; i < path->num_nodes; i++) { |
444 | node = path->reqs[i].node; | |
445 | ||
446 | /* update the consumer request for this path */ | |
447 | path->reqs[i].avg_bw = avg_bw; | |
448 | path->reqs[i].peak_bw = peak_bw; | |
449 | ||
450 | /* aggregate requests for this node */ | |
451 | aggregate_requests(node); | |
452 | } | |
453 | ||
454 | ret = apply_constraints(path); | |
dce6d406 | 455 | if (ret) { |
11f1ceca GD |
456 | pr_debug("interconnect: error applying constraints (%d)\n", |
457 | ret); | |
458 | ||
dce6d406 GD |
459 | for (i = 0; i < path->num_nodes; i++) { |
460 | node = path->reqs[i].node; | |
461 | path->reqs[i].avg_bw = old_avg; | |
462 | path->reqs[i].peak_bw = old_peak; | |
463 | aggregate_requests(node); | |
464 | } | |
465 | apply_constraints(path); | |
466 | } | |
467 | ||
11f1ceca GD |
468 | mutex_unlock(&icc_lock); |
469 | ||
470 | return ret; | |
471 | } | |
472 | EXPORT_SYMBOL_GPL(icc_set_bw); | |
473 | ||
474 | /** | |
475 | * icc_get() - return a handle for path between two endpoints | |
476 | * @dev: the device requesting the path | |
477 | * @src_id: source device port id | |
478 | * @dst_id: destination device port id | |
479 | * | |
480 | * This function will search for a path between two endpoints and return an | |
481 | * icc_path handle on success. Use icc_put() to release | |
482 | * constraints when they are not needed anymore. | |
483 | * If the interconnect API is disabled, NULL is returned and the consumer | |
484 | * drivers will still build. Drivers are free to handle this specifically, | |
485 | * but they don't have to. | |
486 | * | |
487 | * Return: icc_path pointer on success, ERR_PTR() on error or NULL if the | |
488 | * interconnect API is disabled. | |
489 | */ | |
490 | struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id) | |
491 | { | |
492 | struct icc_node *src, *dst; | |
493 | struct icc_path *path = ERR_PTR(-EPROBE_DEFER); | |
494 | ||
495 | mutex_lock(&icc_lock); | |
496 | ||
497 | src = node_find(src_id); | |
498 | if (!src) | |
499 | goto out; | |
500 | ||
501 | dst = node_find(dst_id); | |
502 | if (!dst) | |
503 | goto out; | |
504 | ||
505 | path = path_find(dev, src, dst); | |
506 | if (IS_ERR(path)) | |
507 | dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); | |
508 | ||
509 | out: | |
510 | mutex_unlock(&icc_lock); | |
511 | return path; | |
512 | } | |
513 | EXPORT_SYMBOL_GPL(icc_get); | |
514 | ||
515 | /** | |
516 | * icc_put() - release the reference to the icc_path | |
517 | * @path: interconnect path | |
518 | * | |
519 | * Use this function to release the constraints on a path when the path is | |
520 | * no longer needed. The constraints will be re-aggregated. | |
521 | */ | |
522 | void icc_put(struct icc_path *path) | |
523 | { | |
524 | struct icc_node *node; | |
525 | size_t i; | |
526 | int ret; | |
527 | ||
528 | if (!path || WARN_ON(IS_ERR(path))) | |
529 | return; | |
530 | ||
531 | ret = icc_set_bw(path, 0, 0); | |
532 | if (ret) | |
533 | pr_err("%s: error (%d)\n", __func__, ret); | |
534 | ||
535 | mutex_lock(&icc_lock); | |
536 | for (i = 0; i < path->num_nodes; i++) { | |
537 | node = path->reqs[i].node; | |
538 | hlist_del(&path->reqs[i].req_node); | |
539 | if (!WARN_ON(!node->provider->users)) | |
540 | node->provider->users--; | |
541 | } | |
542 | mutex_unlock(&icc_lock); | |
543 | ||
544 | kfree(path); | |
545 | } | |
546 | EXPORT_SYMBOL_GPL(icc_put); | |
547 | ||
548 | static struct icc_node *icc_node_create_nolock(int id) | |
549 | { | |
550 | struct icc_node *node; | |
551 | ||
552 | /* check if node already exists */ | |
553 | node = node_find(id); | |
554 | if (node) | |
555 | return node; | |
556 | ||
557 | node = kzalloc(sizeof(*node), GFP_KERNEL); | |
558 | if (!node) | |
559 | return ERR_PTR(-ENOMEM); | |
560 | ||
561 | id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL); | |
562 | if (id < 0) { | |
563 | WARN(1, "%s: couldn't get idr\n", __func__); | |
564 | kfree(node); | |
565 | return ERR_PTR(id); | |
566 | } | |
567 | ||
568 | node->id = id; | |
569 | ||
570 | return node; | |
571 | } | |
572 | ||
573 | /** | |
574 | * icc_node_create() - create a node | |
575 | * @id: node id | |
576 | * | |
577 | * Return: icc_node pointer on success, or ERR_PTR() on error | |
578 | */ | |
579 | struct icc_node *icc_node_create(int id) | |
580 | { | |
581 | struct icc_node *node; | |
582 | ||
583 | mutex_lock(&icc_lock); | |
584 | ||
585 | node = icc_node_create_nolock(id); | |
586 | ||
587 | mutex_unlock(&icc_lock); | |
588 | ||
589 | return node; | |
590 | } | |
591 | EXPORT_SYMBOL_GPL(icc_node_create); | |
592 | ||
593 | /** | |
594 | * icc_node_destroy() - destroy a node | |
595 | * @id: node id | |
596 | */ | |
597 | void icc_node_destroy(int id) | |
598 | { | |
599 | struct icc_node *node; | |
600 | ||
601 | mutex_lock(&icc_lock); | |
602 | ||
603 | node = node_find(id); | |
604 | if (node) { | |
605 | idr_remove(&icc_idr, node->id); | |
606 | WARN_ON(!hlist_empty(&node->req_list)); | |
607 | } | |
608 | ||
609 | mutex_unlock(&icc_lock); | |
610 | ||
611 | kfree(node); | |
612 | } | |
613 | EXPORT_SYMBOL_GPL(icc_node_destroy); | |
614 | ||
615 | /** | |
616 | * icc_link_create() - create a link between two nodes | |
617 | * @node: source node id | |
618 | * @dst_id: destination node id | |
619 | * | |
620 | * Create a link between two nodes. The nodes might belong to different | |
621 | * interconnect providers and the @dst_id node might not exist (if the | |
622 | * provider driver has not probed yet). So just create the @dst_id node | |
623 | * and when the actual provider driver is probed, the rest of the node | |
624 | * data is filled. | |
625 | * | |
626 | * Return: 0 on success, or an error code otherwise | |
627 | */ | |
628 | int icc_link_create(struct icc_node *node, const int dst_id) | |
629 | { | |
630 | struct icc_node *dst; | |
631 | struct icc_node **new; | |
632 | int ret = 0; | |
633 | ||
634 | if (!node->provider) | |
635 | return -EINVAL; | |
636 | ||
637 | mutex_lock(&icc_lock); | |
638 | ||
639 | dst = node_find(dst_id); | |
640 | if (!dst) { | |
641 | dst = icc_node_create_nolock(dst_id); | |
642 | ||
643 | if (IS_ERR(dst)) { | |
644 | ret = PTR_ERR(dst); | |
645 | goto out; | |
646 | } | |
647 | } | |
648 | ||
649 | new = krealloc(node->links, | |
650 | (node->num_links + 1) * sizeof(*node->links), | |
651 | GFP_KERNEL); | |
652 | if (!new) { | |
653 | ret = -ENOMEM; | |
654 | goto out; | |
655 | } | |
656 | ||
657 | node->links = new; | |
658 | node->links[node->num_links++] = dst; | |
659 | ||
660 | out: | |
661 | mutex_unlock(&icc_lock); | |
662 | ||
663 | return ret; | |
664 | } | |
665 | EXPORT_SYMBOL_GPL(icc_link_create); | |
666 | ||
667 | /** | |
668 | * icc_link_destroy() - destroy a link between two nodes | |
669 | * @src: pointer to source node | |
670 | * @dst: pointer to destination node | |
671 | * | |
672 | * Return: 0 on success, or an error code otherwise | |
673 | */ | |
674 | int icc_link_destroy(struct icc_node *src, struct icc_node *dst) | |
675 | { | |
676 | struct icc_node **new; | |
677 | size_t slot; | |
678 | int ret = 0; | |
679 | ||
680 | if (IS_ERR_OR_NULL(src)) | |
681 | return -EINVAL; | |
682 | ||
683 | if (IS_ERR_OR_NULL(dst)) | |
684 | return -EINVAL; | |
685 | ||
686 | mutex_lock(&icc_lock); | |
687 | ||
688 | for (slot = 0; slot < src->num_links; slot++) | |
689 | if (src->links[slot] == dst) | |
690 | break; | |
691 | ||
692 | if (WARN_ON(slot == src->num_links)) { | |
693 | ret = -ENXIO; | |
694 | goto out; | |
695 | } | |
696 | ||
697 | src->links[slot] = src->links[--src->num_links]; | |
698 | ||
699 | new = krealloc(src->links, src->num_links * sizeof(*src->links), | |
700 | GFP_KERNEL); | |
701 | if (new) | |
702 | src->links = new; | |
703 | ||
704 | out: | |
705 | mutex_unlock(&icc_lock); | |
706 | ||
707 | return ret; | |
708 | } | |
709 | EXPORT_SYMBOL_GPL(icc_link_destroy); | |
710 | ||
711 | /** | |
712 | * icc_node_add() - add interconnect node to interconnect provider | |
713 | * @node: pointer to the interconnect node | |
714 | * @provider: pointer to the interconnect provider | |
715 | */ | |
716 | void icc_node_add(struct icc_node *node, struct icc_provider *provider) | |
717 | { | |
718 | mutex_lock(&icc_lock); | |
719 | ||
720 | node->provider = provider; | |
721 | list_add_tail(&node->node_list, &provider->nodes); | |
722 | ||
723 | mutex_unlock(&icc_lock); | |
724 | } | |
725 | EXPORT_SYMBOL_GPL(icc_node_add); | |
726 | ||
727 | /** | |
728 | * icc_node_del() - delete interconnect node from interconnect provider | |
729 | * @node: pointer to the interconnect node | |
730 | */ | |
731 | void icc_node_del(struct icc_node *node) | |
732 | { | |
733 | mutex_lock(&icc_lock); | |
734 | ||
735 | list_del(&node->node_list); | |
736 | ||
737 | mutex_unlock(&icc_lock); | |
738 | } | |
739 | EXPORT_SYMBOL_GPL(icc_node_del); | |
740 | ||
741 | /** | |
742 | * icc_provider_add() - add a new interconnect provider | |
743 | * @provider: the interconnect provider that will be added into topology | |
744 | * | |
745 | * Return: 0 on success, or an error code otherwise | |
746 | */ | |
747 | int icc_provider_add(struct icc_provider *provider) | |
748 | { | |
749 | if (WARN_ON(!provider->set)) | |
750 | return -EINVAL; | |
87e3031b GD |
751 | if (WARN_ON(!provider->xlate)) |
752 | return -EINVAL; | |
11f1ceca GD |
753 | |
754 | mutex_lock(&icc_lock); | |
755 | ||
756 | INIT_LIST_HEAD(&provider->nodes); | |
757 | list_add_tail(&provider->provider_list, &icc_providers); | |
758 | ||
759 | mutex_unlock(&icc_lock); | |
760 | ||
761 | dev_dbg(provider->dev, "interconnect provider added to topology\n"); | |
762 | ||
763 | return 0; | |
764 | } | |
765 | EXPORT_SYMBOL_GPL(icc_provider_add); | |
766 | ||
767 | /** | |
768 | * icc_provider_del() - delete previously added interconnect provider | |
769 | * @provider: the interconnect provider that will be removed from topology | |
770 | * | |
771 | * Return: 0 on success, or an error code otherwise | |
772 | */ | |
773 | int icc_provider_del(struct icc_provider *provider) | |
774 | { | |
775 | mutex_lock(&icc_lock); | |
776 | if (provider->users) { | |
777 | pr_warn("interconnect provider still has %d users\n", | |
778 | provider->users); | |
779 | mutex_unlock(&icc_lock); | |
780 | return -EBUSY; | |
781 | } | |
782 | ||
783 | if (!list_empty(&provider->nodes)) { | |
784 | pr_warn("interconnect provider still has nodes\n"); | |
785 | mutex_unlock(&icc_lock); | |
786 | return -EBUSY; | |
787 | } | |
788 | ||
789 | list_del(&provider->provider_list); | |
790 | mutex_unlock(&icc_lock); | |
791 | ||
792 | return 0; | |
793 | } | |
794 | EXPORT_SYMBOL_GPL(icc_provider_del); | |
795 | ||
3697ff43 GD |
796 | static int __init icc_init(void) |
797 | { | |
798 | icc_debugfs_dir = debugfs_create_dir("interconnect", NULL); | |
799 | debugfs_create_file("interconnect_summary", 0444, | |
800 | icc_debugfs_dir, NULL, &icc_summary_fops); | |
801 | return 0; | |
802 | } | |
803 | ||
804 | static void __exit icc_exit(void) | |
805 | { | |
806 | debugfs_remove_recursive(icc_debugfs_dir); | |
807 | } | |
808 | module_init(icc_init); | |
809 | module_exit(icc_exit); | |
810 | ||
11f1ceca GD |
811 | MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>"); |
812 | MODULE_DESCRIPTION("Interconnect Driver Core"); | |
813 | MODULE_LICENSE("GPL v2"); |