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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/debugfs.h>
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>
19#include <linux/of.h>
20#include <linux/overflow.h>
21
22#include "internal.h"
23
24#define CREATE_TRACE_POINTS
25#include "trace.h"
26
27static DEFINE_IDR(icc_idr);
28static LIST_HEAD(icc_providers);
29static int providers_count;
30static bool synced_state;
31static DEFINE_MUTEX(icc_lock);
32static struct dentry *icc_debugfs_dir;
33
34static void icc_summary_show_one(struct seq_file *s, struct icc_node *n)
35{
36 if (!n)
37 return;
38
39 seq_printf(s, "%-42s %12u %12u\n",
40 n->name, n->avg_bw, n->peak_bw);
41}
42
43static int icc_summary_show(struct seq_file *s, void *data)
44{
45 struct icc_provider *provider;
46
47 seq_puts(s, " node tag avg peak\n");
48 seq_puts(s, "--------------------------------------------------------------------\n");
49
50 mutex_lock(&icc_lock);
51
52 list_for_each_entry(provider, &icc_providers, provider_list) {
53 struct icc_node *n;
54
55 list_for_each_entry(n, &provider->nodes, node_list) {
56 struct icc_req *r;
57
58 icc_summary_show_one(s, n);
59 hlist_for_each_entry(r, &n->req_list, req_node) {
60 u32 avg_bw = 0, peak_bw = 0;
61
62 if (!r->dev)
63 continue;
64
65 if (r->enabled) {
66 avg_bw = r->avg_bw;
67 peak_bw = r->peak_bw;
68 }
69
70 seq_printf(s, " %-27s %12u %12u %12u\n",
71 dev_name(r->dev), r->tag, avg_bw, peak_bw);
72 }
73 }
74 }
75
76 mutex_unlock(&icc_lock);
77
78 return 0;
79}
80DEFINE_SHOW_ATTRIBUTE(icc_summary);
81
82static void icc_graph_show_link(struct seq_file *s, int level,
83 struct icc_node *n, struct icc_node *m)
84{
85 seq_printf(s, "%s\"%d:%s\" -> \"%d:%s\"\n",
86 level == 2 ? "\t\t" : "\t",
87 n->id, n->name, m->id, m->name);
88}
89
90static void icc_graph_show_node(struct seq_file *s, struct icc_node *n)
91{
92 seq_printf(s, "\t\t\"%d:%s\" [label=\"%d:%s",
93 n->id, n->name, n->id, n->name);
94 seq_printf(s, "\n\t\t\t|avg_bw=%ukBps", n->avg_bw);
95 seq_printf(s, "\n\t\t\t|peak_bw=%ukBps", n->peak_bw);
96 seq_puts(s, "\"]\n");
97}
98
99static int icc_graph_show(struct seq_file *s, void *data)
100{
101 struct icc_provider *provider;
102 struct icc_node *n;
103 int cluster_index = 0;
104 int i;
105
106 seq_puts(s, "digraph {\n\trankdir = LR\n\tnode [shape = record]\n");
107 mutex_lock(&icc_lock);
108
109 /* draw providers as cluster subgraphs */
110 cluster_index = 0;
111 list_for_each_entry(provider, &icc_providers, provider_list) {
112 seq_printf(s, "\tsubgraph cluster_%d {\n", ++cluster_index);
113 if (provider->dev)
114 seq_printf(s, "\t\tlabel = \"%s\"\n",
115 dev_name(provider->dev));
116
117 /* draw nodes */
118 list_for_each_entry(n, &provider->nodes, node_list)
119 icc_graph_show_node(s, n);
120
121 /* draw internal links */
122 list_for_each_entry(n, &provider->nodes, node_list)
123 for (i = 0; i < n->num_links; ++i)
124 if (n->provider == n->links[i]->provider)
125 icc_graph_show_link(s, 2, n,
126 n->links[i]);
127
128 seq_puts(s, "\t}\n");
129 }
130
131 /* draw external links */
132 list_for_each_entry(provider, &icc_providers, provider_list)
133 list_for_each_entry(n, &provider->nodes, node_list)
134 for (i = 0; i < n->num_links; ++i)
135 if (n->provider != n->links[i]->provider)
136 icc_graph_show_link(s, 1, n,
137 n->links[i]);
138
139 mutex_unlock(&icc_lock);
140 seq_puts(s, "}");
141
142 return 0;
143}
144DEFINE_SHOW_ATTRIBUTE(icc_graph);
145
146static struct icc_node *node_find(const int id)
147{
148 return idr_find(&icc_idr, id);
149}
150
151static struct icc_path *path_init(struct device *dev, struct icc_node *dst,
152 ssize_t num_nodes)
153{
154 struct icc_node *node = dst;
155 struct icc_path *path;
156 int i;
157
158 path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL);
159 if (!path)
160 return ERR_PTR(-ENOMEM);
161
162 path->num_nodes = num_nodes;
163
164 for (i = num_nodes - 1; i >= 0; i--) {
165 node->provider->users++;
166 hlist_add_head(&path->reqs[i].req_node, &node->req_list);
167 path->reqs[i].node = node;
168 path->reqs[i].dev = dev;
169 path->reqs[i].enabled = true;
170 /* reference to previous node was saved during path traversal */
171 node = node->reverse;
172 }
173
174 return path;
175}
176
177static struct icc_path *path_find(struct device *dev, struct icc_node *src,
178 struct icc_node *dst)
179{
180 struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
181 struct icc_node *n, *node = NULL;
182 struct list_head traverse_list;
183 struct list_head edge_list;
184 struct list_head visited_list;
185 size_t i, depth = 1;
186 bool found = false;
187
188 INIT_LIST_HEAD(&traverse_list);
189 INIT_LIST_HEAD(&edge_list);
190 INIT_LIST_HEAD(&visited_list);
191
192 list_add(&src->search_list, &traverse_list);
193 src->reverse = NULL;
194
195 do {
196 list_for_each_entry_safe(node, n, &traverse_list, search_list) {
197 if (node == dst) {
198 found = true;
199 list_splice_init(&edge_list, &visited_list);
200 list_splice_init(&traverse_list, &visited_list);
201 break;
202 }
203 for (i = 0; i < node->num_links; i++) {
204 struct icc_node *tmp = node->links[i];
205
206 if (!tmp) {
207 path = ERR_PTR(-ENOENT);
208 goto out;
209 }
210
211 if (tmp->is_traversed)
212 continue;
213
214 tmp->is_traversed = true;
215 tmp->reverse = node;
216 list_add_tail(&tmp->search_list, &edge_list);
217 }
218 }
219
220 if (found)
221 break;
222
223 list_splice_init(&traverse_list, &visited_list);
224 list_splice_init(&edge_list, &traverse_list);
225
226 /* count the hops including the source */
227 depth++;
228
229 } while (!list_empty(&traverse_list));
230
231out:
232
233 /* reset the traversed state */
234 list_for_each_entry_reverse(n, &visited_list, search_list)
235 n->is_traversed = false;
236
237 if (found)
238 path = path_init(dev, dst, depth);
239
240 return path;
241}
242
243/*
244 * We want the path to honor all bandwidth requests, so the average and peak
245 * bandwidth requirements from each consumer are aggregated at each node.
246 * The aggregation is platform specific, so each platform can customize it by
247 * implementing its own aggregate() function.
248 */
249
250static int aggregate_requests(struct icc_node *node)
251{
252 struct icc_provider *p = node->provider;
253 struct icc_req *r;
254 u32 avg_bw, peak_bw;
255
256 node->avg_bw = 0;
257 node->peak_bw = 0;
258
259 if (p->pre_aggregate)
260 p->pre_aggregate(node);
261
262 hlist_for_each_entry(r, &node->req_list, req_node) {
263 if (r->enabled) {
264 avg_bw = r->avg_bw;
265 peak_bw = r->peak_bw;
266 } else {
267 avg_bw = 0;
268 peak_bw = 0;
269 }
270 p->aggregate(node, r->tag, avg_bw, peak_bw,
271 &node->avg_bw, &node->peak_bw);
272
273 /* during boot use the initial bandwidth as a floor value */
274 if (!synced_state) {
275 node->avg_bw = max(node->avg_bw, node->init_avg);
276 node->peak_bw = max(node->peak_bw, node->init_peak);
277 }
278 }
279
280 return 0;
281}
282
283static int apply_constraints(struct icc_path *path)
284{
285 struct icc_node *next, *prev = NULL;
286 struct icc_provider *p;
287 int ret = -EINVAL;
288 int i;
289
290 for (i = 0; i < path->num_nodes; i++) {
291 next = path->reqs[i].node;
292 p = next->provider;
293
294 /* both endpoints should be valid master-slave pairs */
295 if (!prev || (p != prev->provider && !p->inter_set)) {
296 prev = next;
297 continue;
298 }
299
300 /* set the constraints */
301 ret = p->set(prev, next);
302 if (ret)
303 goto out;
304
305 prev = next;
306 }
307out:
308 return ret;
309}
310
311int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
312 u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
313{
314 *agg_avg += avg_bw;
315 *agg_peak = max(*agg_peak, peak_bw);
316
317 return 0;
318}
319EXPORT_SYMBOL_GPL(icc_std_aggregate);
320
321/* of_icc_xlate_onecell() - Translate function using a single index.
322 * @spec: OF phandle args to map into an interconnect node.
323 * @data: private data (pointer to struct icc_onecell_data)
324 *
325 * This is a generic translate function that can be used to model simple
326 * interconnect providers that have one device tree node and provide
327 * multiple interconnect nodes. A single cell is used as an index into
328 * an array of icc nodes specified in the icc_onecell_data struct when
329 * registering the provider.
330 */
331struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec,
332 void *data)
333{
334 struct icc_onecell_data *icc_data = data;
335 unsigned int idx = spec->args[0];
336
337 if (idx >= icc_data->num_nodes) {
338 pr_err("%s: invalid index %u\n", __func__, idx);
339 return ERR_PTR(-EINVAL);
340 }
341
342 return icc_data->nodes[idx];
343}
344EXPORT_SYMBOL_GPL(of_icc_xlate_onecell);
345
346/**
347 * of_icc_get_from_provider() - Look-up interconnect node
348 * @spec: OF phandle args to use for look-up
349 *
350 * Looks for interconnect provider under the node specified by @spec and if
351 * found, uses xlate function of the provider to map phandle args to node.
352 *
353 * Returns a valid pointer to struct icc_node_data on success or ERR_PTR()
354 * on failure.
355 */
356struct icc_node_data *of_icc_get_from_provider(struct of_phandle_args *spec)
357{
358 struct icc_node *node = ERR_PTR(-EPROBE_DEFER);
359 struct icc_node_data *data = NULL;
360 struct icc_provider *provider;
361
362 if (!spec)
363 return ERR_PTR(-EINVAL);
364
365 mutex_lock(&icc_lock);
366 list_for_each_entry(provider, &icc_providers, provider_list) {
367 if (provider->dev->of_node == spec->np) {
368 if (provider->xlate_extended) {
369 data = provider->xlate_extended(spec, provider->data);
370 if (!IS_ERR(data)) {
371 node = data->node;
372 break;
373 }
374 } else {
375 node = provider->xlate(spec, provider->data);
376 if (!IS_ERR(node))
377 break;
378 }
379 }
380 }
381 mutex_unlock(&icc_lock);
382
383 if (IS_ERR(node))
384 return ERR_CAST(node);
385
386 if (!data) {
387 data = kzalloc(sizeof(*data), GFP_KERNEL);
388 if (!data)
389 return ERR_PTR(-ENOMEM);
390 data->node = node;
391 }
392
393 return data;
394}
395EXPORT_SYMBOL_GPL(of_icc_get_from_provider);
396
397static void devm_icc_release(struct device *dev, void *res)
398{
399 icc_put(*(struct icc_path **)res);
400}
401
402struct icc_path *devm_of_icc_get(struct device *dev, const char *name)
403{
404 struct icc_path **ptr, *path;
405
406 ptr = devres_alloc(devm_icc_release, sizeof(*ptr), GFP_KERNEL);
407 if (!ptr)
408 return ERR_PTR(-ENOMEM);
409
410 path = of_icc_get(dev, name);
411 if (!IS_ERR(path)) {
412 *ptr = path;
413 devres_add(dev, ptr);
414 } else {
415 devres_free(ptr);
416 }
417
418 return path;
419}
420EXPORT_SYMBOL_GPL(devm_of_icc_get);
421
422/**
423 * of_icc_get_by_index() - get a path handle from a DT node based on index
424 * @dev: device pointer for the consumer device
425 * @idx: interconnect path index
426 *
427 * This function will search for a path between two endpoints and return an
428 * icc_path handle on success. Use icc_put() to release constraints when they
429 * are not needed anymore.
430 * If the interconnect API is disabled, NULL is returned and the consumer
431 * drivers will still build. Drivers are free to handle this specifically,
432 * but they don't have to.
433 *
434 * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
435 * when the API is disabled or the "interconnects" DT property is missing.
436 */
437struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
438{
439 struct icc_path *path;
440 struct icc_node_data *src_data, *dst_data;
441 struct device_node *np;
442 struct of_phandle_args src_args, dst_args;
443 int ret;
444
445 if (!dev || !dev->of_node)
446 return ERR_PTR(-ENODEV);
447
448 np = dev->of_node;
449
450 /*
451 * When the consumer DT node do not have "interconnects" property
452 * return a NULL path to skip setting constraints.
453 */
454 if (!of_find_property(np, "interconnects", NULL))
455 return NULL;
456
457 /*
458 * We use a combination of phandle and specifier for endpoint. For now
459 * lets support only global ids and extend this in the future if needed
460 * without breaking DT compatibility.
461 */
462 ret = of_parse_phandle_with_args(np, "interconnects",
463 "#interconnect-cells", idx * 2,
464 &src_args);
465 if (ret)
466 return ERR_PTR(ret);
467
468 of_node_put(src_args.np);
469
470 ret = of_parse_phandle_with_args(np, "interconnects",
471 "#interconnect-cells", idx * 2 + 1,
472 &dst_args);
473 if (ret)
474 return ERR_PTR(ret);
475
476 of_node_put(dst_args.np);
477
478 src_data = of_icc_get_from_provider(&src_args);
479
480 if (IS_ERR(src_data)) {
481 dev_err_probe(dev, PTR_ERR(src_data), "error finding src node\n");
482 return ERR_CAST(src_data);
483 }
484
485 dst_data = of_icc_get_from_provider(&dst_args);
486
487 if (IS_ERR(dst_data)) {
488 dev_err_probe(dev, PTR_ERR(dst_data), "error finding dst node\n");
489 kfree(src_data);
490 return ERR_CAST(dst_data);
491 }
492
493 mutex_lock(&icc_lock);
494 path = path_find(dev, src_data->node, dst_data->node);
495 mutex_unlock(&icc_lock);
496 if (IS_ERR(path)) {
497 dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
498 goto free_icc_data;
499 }
500
501 if (src_data->tag && src_data->tag == dst_data->tag)
502 icc_set_tag(path, src_data->tag);
503
504 path->name = kasprintf(GFP_KERNEL, "%s-%s",
505 src_data->node->name, dst_data->node->name);
506 if (!path->name) {
507 kfree(path);
508 path = ERR_PTR(-ENOMEM);
509 }
510
511free_icc_data:
512 kfree(src_data);
513 kfree(dst_data);
514 return path;
515}
516EXPORT_SYMBOL_GPL(of_icc_get_by_index);
517
518/**
519 * of_icc_get() - get a path handle from a DT node based on name
520 * @dev: device pointer for the consumer device
521 * @name: interconnect path name
522 *
523 * This function will search for a path between two endpoints and return an
524 * icc_path handle on success. Use icc_put() to release constraints when they
525 * are not needed anymore.
526 * If the interconnect API is disabled, NULL is returned and the consumer
527 * drivers will still build. Drivers are free to handle this specifically,
528 * but they don't have to.
529 *
530 * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
531 * when the API is disabled or the "interconnects" DT property is missing.
532 */
533struct icc_path *of_icc_get(struct device *dev, const char *name)
534{
535 struct device_node *np;
536 int idx = 0;
537
538 if (!dev || !dev->of_node)
539 return ERR_PTR(-ENODEV);
540
541 np = dev->of_node;
542
543 /*
544 * When the consumer DT node do not have "interconnects" property
545 * return a NULL path to skip setting constraints.
546 */
547 if (!of_find_property(np, "interconnects", NULL))
548 return NULL;
549
550 /*
551 * We use a combination of phandle and specifier for endpoint. For now
552 * lets support only global ids and extend this in the future if needed
553 * without breaking DT compatibility.
554 */
555 if (name) {
556 idx = of_property_match_string(np, "interconnect-names", name);
557 if (idx < 0)
558 return ERR_PTR(idx);
559 }
560
561 return of_icc_get_by_index(dev, idx);
562}
563EXPORT_SYMBOL_GPL(of_icc_get);
564
565/**
566 * icc_set_tag() - set an optional tag on a path
567 * @path: the path we want to tag
568 * @tag: the tag value
569 *
570 * This function allows consumers to append a tag to the requests associated
571 * with a path, so that a different aggregation could be done based on this tag.
572 */
573void icc_set_tag(struct icc_path *path, u32 tag)
574{
575 int i;
576
577 if (!path)
578 return;
579
580 mutex_lock(&icc_lock);
581
582 for (i = 0; i < path->num_nodes; i++)
583 path->reqs[i].tag = tag;
584
585 mutex_unlock(&icc_lock);
586}
587EXPORT_SYMBOL_GPL(icc_set_tag);
588
589/**
590 * icc_get_name() - Get name of the icc path
591 * @path: reference to the path returned by icc_get()
592 *
593 * This function is used by an interconnect consumer to get the name of the icc
594 * path.
595 *
596 * Returns a valid pointer on success, or NULL otherwise.
597 */
598const char *icc_get_name(struct icc_path *path)
599{
600 if (!path)
601 return NULL;
602
603 return path->name;
604}
605EXPORT_SYMBOL_GPL(icc_get_name);
606
607/**
608 * icc_set_bw() - set bandwidth constraints on an interconnect path
609 * @path: reference to the path returned by icc_get()
610 * @avg_bw: average bandwidth in kilobytes per second
611 * @peak_bw: peak bandwidth in kilobytes per second
612 *
613 * This function is used by an interconnect consumer to express its own needs
614 * in terms of bandwidth for a previously requested path between two endpoints.
615 * The requests are aggregated and each node is updated accordingly. The entire
616 * path is locked by a mutex to ensure that the set() is completed.
617 * The @path can be NULL when the "interconnects" DT properties is missing,
618 * which will mean that no constraints will be set.
619 *
620 * Returns 0 on success, or an appropriate error code otherwise.
621 */
622int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
623{
624 struct icc_node *node;
625 u32 old_avg, old_peak;
626 size_t i;
627 int ret;
628
629 if (!path)
630 return 0;
631
632 if (WARN_ON(IS_ERR(path) || !path->num_nodes))
633 return -EINVAL;
634
635 mutex_lock(&icc_lock);
636
637 old_avg = path->reqs[0].avg_bw;
638 old_peak = path->reqs[0].peak_bw;
639
640 for (i = 0; i < path->num_nodes; i++) {
641 node = path->reqs[i].node;
642
643 /* update the consumer request for this path */
644 path->reqs[i].avg_bw = avg_bw;
645 path->reqs[i].peak_bw = peak_bw;
646
647 /* aggregate requests for this node */
648 aggregate_requests(node);
649
650 trace_icc_set_bw(path, node, i, avg_bw, peak_bw);
651 }
652
653 ret = apply_constraints(path);
654 if (ret) {
655 pr_debug("interconnect: error applying constraints (%d)\n",
656 ret);
657
658 for (i = 0; i < path->num_nodes; i++) {
659 node = path->reqs[i].node;
660 path->reqs[i].avg_bw = old_avg;
661 path->reqs[i].peak_bw = old_peak;
662 aggregate_requests(node);
663 }
664 apply_constraints(path);
665 }
666
667 mutex_unlock(&icc_lock);
668
669 trace_icc_set_bw_end(path, ret);
670
671 return ret;
672}
673EXPORT_SYMBOL_GPL(icc_set_bw);
674
675static int __icc_enable(struct icc_path *path, bool enable)
676{
677 int i;
678
679 if (!path)
680 return 0;
681
682 if (WARN_ON(IS_ERR(path) || !path->num_nodes))
683 return -EINVAL;
684
685 mutex_lock(&icc_lock);
686
687 for (i = 0; i < path->num_nodes; i++)
688 path->reqs[i].enabled = enable;
689
690 mutex_unlock(&icc_lock);
691
692 return icc_set_bw(path, path->reqs[0].avg_bw,
693 path->reqs[0].peak_bw);
694}
695
696int icc_enable(struct icc_path *path)
697{
698 return __icc_enable(path, true);
699}
700EXPORT_SYMBOL_GPL(icc_enable);
701
702int icc_disable(struct icc_path *path)
703{
704 return __icc_enable(path, false);
705}
706EXPORT_SYMBOL_GPL(icc_disable);
707
708/**
709 * icc_get() - return a handle for path between two endpoints
710 * @dev: the device requesting the path
711 * @src_id: source device port id
712 * @dst_id: destination device port id
713 *
714 * This function will search for a path between two endpoints and return an
715 * icc_path handle on success. Use icc_put() to release
716 * constraints when they are not needed anymore.
717 * If the interconnect API is disabled, NULL is returned and the consumer
718 * drivers will still build. Drivers are free to handle this specifically,
719 * but they don't have to.
720 *
721 * Return: icc_path pointer on success, ERR_PTR() on error or NULL if the
722 * interconnect API is disabled.
723 */
724struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id)
725{
726 struct icc_node *src, *dst;
727 struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
728
729 mutex_lock(&icc_lock);
730
731 src = node_find(src_id);
732 if (!src)
733 goto out;
734
735 dst = node_find(dst_id);
736 if (!dst)
737 goto out;
738
739 path = path_find(dev, src, dst);
740 if (IS_ERR(path)) {
741 dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
742 goto out;
743 }
744
745 path->name = kasprintf(GFP_KERNEL, "%s-%s", src->name, dst->name);
746 if (!path->name) {
747 kfree(path);
748 path = ERR_PTR(-ENOMEM);
749 }
750out:
751 mutex_unlock(&icc_lock);
752 return path;
753}
754EXPORT_SYMBOL_GPL(icc_get);
755
756/**
757 * icc_put() - release the reference to the icc_path
758 * @path: interconnect path
759 *
760 * Use this function to release the constraints on a path when the path is
761 * no longer needed. The constraints will be re-aggregated.
762 */
763void icc_put(struct icc_path *path)
764{
765 struct icc_node *node;
766 size_t i;
767 int ret;
768
769 if (!path || WARN_ON(IS_ERR(path)))
770 return;
771
772 ret = icc_set_bw(path, 0, 0);
773 if (ret)
774 pr_err("%s: error (%d)\n", __func__, ret);
775
776 mutex_lock(&icc_lock);
777 for (i = 0; i < path->num_nodes; i++) {
778 node = path->reqs[i].node;
779 hlist_del(&path->reqs[i].req_node);
780 if (!WARN_ON(!node->provider->users))
781 node->provider->users--;
782 }
783 mutex_unlock(&icc_lock);
784
785 kfree_const(path->name);
786 kfree(path);
787}
788EXPORT_SYMBOL_GPL(icc_put);
789
790static struct icc_node *icc_node_create_nolock(int id)
791{
792 struct icc_node *node;
793
794 /* check if node already exists */
795 node = node_find(id);
796 if (node)
797 return node;
798
799 node = kzalloc(sizeof(*node), GFP_KERNEL);
800 if (!node)
801 return ERR_PTR(-ENOMEM);
802
803 id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL);
804 if (id < 0) {
805 WARN(1, "%s: couldn't get idr\n", __func__);
806 kfree(node);
807 return ERR_PTR(id);
808 }
809
810 node->id = id;
811
812 return node;
813}
814
815/**
816 * icc_node_create() - create a node
817 * @id: node id
818 *
819 * Return: icc_node pointer on success, or ERR_PTR() on error
820 */
821struct icc_node *icc_node_create(int id)
822{
823 struct icc_node *node;
824
825 mutex_lock(&icc_lock);
826
827 node = icc_node_create_nolock(id);
828
829 mutex_unlock(&icc_lock);
830
831 return node;
832}
833EXPORT_SYMBOL_GPL(icc_node_create);
834
835/**
836 * icc_node_destroy() - destroy a node
837 * @id: node id
838 */
839void icc_node_destroy(int id)
840{
841 struct icc_node *node;
842
843 mutex_lock(&icc_lock);
844
845 node = node_find(id);
846 if (node) {
847 idr_remove(&icc_idr, node->id);
848 WARN_ON(!hlist_empty(&node->req_list));
849 }
850
851 mutex_unlock(&icc_lock);
852
853 kfree(node);
854}
855EXPORT_SYMBOL_GPL(icc_node_destroy);
856
857/**
858 * icc_link_create() - create a link between two nodes
859 * @node: source node id
860 * @dst_id: destination node id
861 *
862 * Create a link between two nodes. The nodes might belong to different
863 * interconnect providers and the @dst_id node might not exist (if the
864 * provider driver has not probed yet). So just create the @dst_id node
865 * and when the actual provider driver is probed, the rest of the node
866 * data is filled.
867 *
868 * Return: 0 on success, or an error code otherwise
869 */
870int icc_link_create(struct icc_node *node, const int dst_id)
871{
872 struct icc_node *dst;
873 struct icc_node **new;
874 int ret = 0;
875
876 if (!node->provider)
877 return -EINVAL;
878
879 mutex_lock(&icc_lock);
880
881 dst = node_find(dst_id);
882 if (!dst) {
883 dst = icc_node_create_nolock(dst_id);
884
885 if (IS_ERR(dst)) {
886 ret = PTR_ERR(dst);
887 goto out;
888 }
889 }
890
891 new = krealloc(node->links,
892 (node->num_links + 1) * sizeof(*node->links),
893 GFP_KERNEL);
894 if (!new) {
895 ret = -ENOMEM;
896 goto out;
897 }
898
899 node->links = new;
900 node->links[node->num_links++] = dst;
901
902out:
903 mutex_unlock(&icc_lock);
904
905 return ret;
906}
907EXPORT_SYMBOL_GPL(icc_link_create);
908
909/**
910 * icc_link_destroy() - destroy a link between two nodes
911 * @src: pointer to source node
912 * @dst: pointer to destination node
913 *
914 * Return: 0 on success, or an error code otherwise
915 */
916int icc_link_destroy(struct icc_node *src, struct icc_node *dst)
917{
918 struct icc_node **new;
919 size_t slot;
920 int ret = 0;
921
922 if (IS_ERR_OR_NULL(src))
923 return -EINVAL;
924
925 if (IS_ERR_OR_NULL(dst))
926 return -EINVAL;
927
928 mutex_lock(&icc_lock);
929
930 for (slot = 0; slot < src->num_links; slot++)
931 if (src->links[slot] == dst)
932 break;
933
934 if (WARN_ON(slot == src->num_links)) {
935 ret = -ENXIO;
936 goto out;
937 }
938
939 src->links[slot] = src->links[--src->num_links];
940
941 new = krealloc(src->links, src->num_links * sizeof(*src->links),
942 GFP_KERNEL);
943 if (new)
944 src->links = new;
945 else
946 ret = -ENOMEM;
947
948out:
949 mutex_unlock(&icc_lock);
950
951 return ret;
952}
953EXPORT_SYMBOL_GPL(icc_link_destroy);
954
955/**
956 * icc_node_add() - add interconnect node to interconnect provider
957 * @node: pointer to the interconnect node
958 * @provider: pointer to the interconnect provider
959 */
960void icc_node_add(struct icc_node *node, struct icc_provider *provider)
961{
962 mutex_lock(&icc_lock);
963
964 node->provider = provider;
965 list_add_tail(&node->node_list, &provider->nodes);
966
967 /* get the initial bandwidth values and sync them with hardware */
968 if (provider->get_bw) {
969 provider->get_bw(node, &node->init_avg, &node->init_peak);
970 } else {
971 node->init_avg = INT_MAX;
972 node->init_peak = INT_MAX;
973 }
974 node->avg_bw = node->init_avg;
975 node->peak_bw = node->init_peak;
976
977 if (provider->pre_aggregate)
978 provider->pre_aggregate(node);
979
980 if (provider->aggregate)
981 provider->aggregate(node, 0, node->init_avg, node->init_peak,
982 &node->avg_bw, &node->peak_bw);
983
984 provider->set(node, node);
985 node->avg_bw = 0;
986 node->peak_bw = 0;
987
988 mutex_unlock(&icc_lock);
989}
990EXPORT_SYMBOL_GPL(icc_node_add);
991
992/**
993 * icc_node_del() - delete interconnect node from interconnect provider
994 * @node: pointer to the interconnect node
995 */
996void icc_node_del(struct icc_node *node)
997{
998 mutex_lock(&icc_lock);
999
1000 list_del(&node->node_list);
1001
1002 mutex_unlock(&icc_lock);
1003}
1004EXPORT_SYMBOL_GPL(icc_node_del);
1005
1006/**
1007 * icc_nodes_remove() - remove all previously added nodes from provider
1008 * @provider: the interconnect provider we are removing nodes from
1009 *
1010 * Return: 0 on success, or an error code otherwise
1011 */
1012int icc_nodes_remove(struct icc_provider *provider)
1013{
1014 struct icc_node *n, *tmp;
1015
1016 if (WARN_ON(IS_ERR_OR_NULL(provider)))
1017 return -EINVAL;
1018
1019 list_for_each_entry_safe_reverse(n, tmp, &provider->nodes, node_list) {
1020 icc_node_del(n);
1021 icc_node_destroy(n->id);
1022 }
1023
1024 return 0;
1025}
1026EXPORT_SYMBOL_GPL(icc_nodes_remove);
1027
1028/**
1029 * icc_provider_add() - add a new interconnect provider
1030 * @provider: the interconnect provider that will be added into topology
1031 *
1032 * Return: 0 on success, or an error code otherwise
1033 */
1034int icc_provider_add(struct icc_provider *provider)
1035{
1036 if (WARN_ON(!provider->set))
1037 return -EINVAL;
1038 if (WARN_ON(!provider->xlate && !provider->xlate_extended))
1039 return -EINVAL;
1040
1041 mutex_lock(&icc_lock);
1042
1043 INIT_LIST_HEAD(&provider->nodes);
1044 list_add_tail(&provider->provider_list, &icc_providers);
1045
1046 mutex_unlock(&icc_lock);
1047
1048 dev_dbg(provider->dev, "interconnect provider added to topology\n");
1049
1050 return 0;
1051}
1052EXPORT_SYMBOL_GPL(icc_provider_add);
1053
1054/**
1055 * icc_provider_del() - delete previously added interconnect provider
1056 * @provider: the interconnect provider that will be removed from topology
1057 *
1058 * Return: 0 on success, or an error code otherwise
1059 */
1060int icc_provider_del(struct icc_provider *provider)
1061{
1062 mutex_lock(&icc_lock);
1063 if (provider->users) {
1064 pr_warn("interconnect provider still has %d users\n",
1065 provider->users);
1066 mutex_unlock(&icc_lock);
1067 return -EBUSY;
1068 }
1069
1070 if (!list_empty(&provider->nodes)) {
1071 pr_warn("interconnect provider still has nodes\n");
1072 mutex_unlock(&icc_lock);
1073 return -EBUSY;
1074 }
1075
1076 list_del(&provider->provider_list);
1077 mutex_unlock(&icc_lock);
1078
1079 return 0;
1080}
1081EXPORT_SYMBOL_GPL(icc_provider_del);
1082
1083static int of_count_icc_providers(struct device_node *np)
1084{
1085 struct device_node *child;
1086 int count = 0;
1087
1088 for_each_available_child_of_node(np, child) {
1089 if (of_property_read_bool(child, "#interconnect-cells"))
1090 count++;
1091 count += of_count_icc_providers(child);
1092 }
1093
1094 return count;
1095}
1096
1097void icc_sync_state(struct device *dev)
1098{
1099 struct icc_provider *p;
1100 struct icc_node *n;
1101 static int count;
1102
1103 count++;
1104
1105 if (count < providers_count)
1106 return;
1107
1108 mutex_lock(&icc_lock);
1109 synced_state = true;
1110 list_for_each_entry(p, &icc_providers, provider_list) {
1111 dev_dbg(p->dev, "interconnect provider is in synced state\n");
1112 list_for_each_entry(n, &p->nodes, node_list) {
1113 if (n->init_avg || n->init_peak) {
1114 n->init_avg = 0;
1115 n->init_peak = 0;
1116 aggregate_requests(n);
1117 p->set(n, n);
1118 }
1119 }
1120 }
1121 mutex_unlock(&icc_lock);
1122}
1123EXPORT_SYMBOL_GPL(icc_sync_state);
1124
1125static int __init icc_init(void)
1126{
1127 struct device_node *root = of_find_node_by_path("/");
1128
1129 providers_count = of_count_icc_providers(root);
1130 of_node_put(root);
1131
1132 icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
1133 debugfs_create_file("interconnect_summary", 0444,
1134 icc_debugfs_dir, NULL, &icc_summary_fops);
1135 debugfs_create_file("interconnect_graph", 0444,
1136 icc_debugfs_dir, NULL, &icc_graph_fops);
1137 return 0;
1138}
1139
1140device_initcall(icc_init);
1141
1142MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
1143MODULE_DESCRIPTION("Interconnect Driver Core");
1144MODULE_LICENSE("GPL v2");