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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 if (WARN_ON(node->provider))
963 return;
964
965 mutex_lock(&icc_lock);
966
967 node->provider = provider;
968 list_add_tail(&node->node_list, &provider->nodes);
969
970 /* get the initial bandwidth values and sync them with hardware */
971 if (provider->get_bw) {
972 provider->get_bw(node, &node->init_avg, &node->init_peak);
973 } else {
974 node->init_avg = INT_MAX;
975 node->init_peak = INT_MAX;
976 }
977 node->avg_bw = node->init_avg;
978 node->peak_bw = node->init_peak;
979
980 if (provider->pre_aggregate)
981 provider->pre_aggregate(node);
982
983 if (provider->aggregate)
984 provider->aggregate(node, 0, node->init_avg, node->init_peak,
985 &node->avg_bw, &node->peak_bw);
986
987 provider->set(node, node);
988 node->avg_bw = 0;
989 node->peak_bw = 0;
990
991 mutex_unlock(&icc_lock);
992}
993EXPORT_SYMBOL_GPL(icc_node_add);
994
995/**
996 * icc_node_del() - delete interconnect node from interconnect provider
997 * @node: pointer to the interconnect node
998 */
999void icc_node_del(struct icc_node *node)
1000{
1001 mutex_lock(&icc_lock);
1002
1003 list_del(&node->node_list);
1004
1005 mutex_unlock(&icc_lock);
1006}
1007EXPORT_SYMBOL_GPL(icc_node_del);
1008
1009/**
1010 * icc_nodes_remove() - remove all previously added nodes from provider
1011 * @provider: the interconnect provider we are removing nodes from
1012 *
1013 * Return: 0 on success, or an error code otherwise
1014 */
1015int icc_nodes_remove(struct icc_provider *provider)
1016{
1017 struct icc_node *n, *tmp;
1018
1019 if (WARN_ON(IS_ERR_OR_NULL(provider)))
1020 return -EINVAL;
1021
1022 list_for_each_entry_safe_reverse(n, tmp, &provider->nodes, node_list) {
1023 icc_node_del(n);
1024 icc_node_destroy(n->id);
1025 }
1026
1027 return 0;
1028}
1029EXPORT_SYMBOL_GPL(icc_nodes_remove);
1030
1031/**
1032 * icc_provider_add() - add a new interconnect provider
1033 * @provider: the interconnect provider that will be added into topology
1034 *
1035 * Return: 0 on success, or an error code otherwise
1036 */
1037int icc_provider_add(struct icc_provider *provider)
1038{
1039 if (WARN_ON(!provider->set))
1040 return -EINVAL;
1041 if (WARN_ON(!provider->xlate && !provider->xlate_extended))
1042 return -EINVAL;
1043
1044 mutex_lock(&icc_lock);
1045
1046 INIT_LIST_HEAD(&provider->nodes);
1047 list_add_tail(&provider->provider_list, &icc_providers);
1048
1049 mutex_unlock(&icc_lock);
1050
1051 dev_dbg(provider->dev, "interconnect provider added to topology\n");
1052
1053 return 0;
1054}
1055EXPORT_SYMBOL_GPL(icc_provider_add);
1056
1057/**
1058 * icc_provider_del() - delete previously added interconnect provider
1059 * @provider: the interconnect provider that will be removed from topology
1060 */
1061void icc_provider_del(struct icc_provider *provider)
1062{
1063 mutex_lock(&icc_lock);
1064 if (provider->users) {
1065 pr_warn("interconnect provider still has %d users\n",
1066 provider->users);
1067 mutex_unlock(&icc_lock);
1068 return;
1069 }
1070
1071 if (!list_empty(&provider->nodes)) {
1072 pr_warn("interconnect provider still has nodes\n");
1073 mutex_unlock(&icc_lock);
1074 return;
1075 }
1076
1077 list_del(&provider->provider_list);
1078 mutex_unlock(&icc_lock);
1079}
1080EXPORT_SYMBOL_GPL(icc_provider_del);
1081
1082static int of_count_icc_providers(struct device_node *np)
1083{
1084 struct device_node *child;
1085 int count = 0;
1086 const struct of_device_id __maybe_unused ignore_list[] = {
1087 { .compatible = "qcom,sc7180-ipa-virt" },
1088 { .compatible = "qcom,sdx55-ipa-virt" },
1089 {}
1090 };
1091
1092 for_each_available_child_of_node(np, child) {
1093 if (of_property_read_bool(child, "#interconnect-cells") &&
1094 likely(!of_match_node(ignore_list, child)))
1095 count++;
1096 count += of_count_icc_providers(child);
1097 }
1098
1099 return count;
1100}
1101
1102void icc_sync_state(struct device *dev)
1103{
1104 struct icc_provider *p;
1105 struct icc_node *n;
1106 static int count;
1107
1108 count++;
1109
1110 if (count < providers_count)
1111 return;
1112
1113 mutex_lock(&icc_lock);
1114 synced_state = true;
1115 list_for_each_entry(p, &icc_providers, provider_list) {
1116 dev_dbg(p->dev, "interconnect provider is in synced state\n");
1117 list_for_each_entry(n, &p->nodes, node_list) {
1118 if (n->init_avg || n->init_peak) {
1119 n->init_avg = 0;
1120 n->init_peak = 0;
1121 aggregate_requests(n);
1122 p->set(n, n);
1123 }
1124 }
1125 }
1126 mutex_unlock(&icc_lock);
1127}
1128EXPORT_SYMBOL_GPL(icc_sync_state);
1129
1130static int __init icc_init(void)
1131{
1132 struct device_node *root = of_find_node_by_path("/");
1133
1134 providers_count = of_count_icc_providers(root);
1135 of_node_put(root);
1136
1137 icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
1138 debugfs_create_file("interconnect_summary", 0444,
1139 icc_debugfs_dir, NULL, &icc_summary_fops);
1140 debugfs_create_file("interconnect_graph", 0444,
1141 icc_debugfs_dir, NULL, &icc_graph_fops);
1142 return 0;
1143}
1144
1145device_initcall(icc_init);
1146
1147MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
1148MODULE_DESCRIPTION("Interconnect Driver Core");
1149MODULE_LICENSE("GPL v2");
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 DEFINE_MUTEX(icc_lock);
30static struct dentry *icc_debugfs_dir;
31
32static void icc_summary_show_one(struct seq_file *s, struct icc_node *n)
33{
34 if (!n)
35 return;
36
37 seq_printf(s, "%-42s %12u %12u\n",
38 n->name, n->avg_bw, n->peak_bw);
39}
40
41static int icc_summary_show(struct seq_file *s, void *data)
42{
43 struct icc_provider *provider;
44
45 seq_puts(s, " node tag avg peak\n");
46 seq_puts(s, "--------------------------------------------------------------------\n");
47
48 mutex_lock(&icc_lock);
49
50 list_for_each_entry(provider, &icc_providers, provider_list) {
51 struct icc_node *n;
52
53 list_for_each_entry(n, &provider->nodes, node_list) {
54 struct icc_req *r;
55
56 icc_summary_show_one(s, n);
57 hlist_for_each_entry(r, &n->req_list, req_node) {
58 u32 avg_bw = 0, peak_bw = 0;
59
60 if (!r->dev)
61 continue;
62
63 if (r->enabled) {
64 avg_bw = r->avg_bw;
65 peak_bw = r->peak_bw;
66 }
67
68 seq_printf(s, " %-27s %12u %12u %12u\n",
69 dev_name(r->dev), r->tag, avg_bw, peak_bw);
70 }
71 }
72 }
73
74 mutex_unlock(&icc_lock);
75
76 return 0;
77}
78DEFINE_SHOW_ATTRIBUTE(icc_summary);
79
80static void icc_graph_show_link(struct seq_file *s, int level,
81 struct icc_node *n, struct icc_node *m)
82{
83 seq_printf(s, "%s\"%d:%s\" -> \"%d:%s\"\n",
84 level == 2 ? "\t\t" : "\t",
85 n->id, n->name, m->id, m->name);
86}
87
88static void icc_graph_show_node(struct seq_file *s, struct icc_node *n)
89{
90 seq_printf(s, "\t\t\"%d:%s\" [label=\"%d:%s",
91 n->id, n->name, n->id, n->name);
92 seq_printf(s, "\n\t\t\t|avg_bw=%ukBps", n->avg_bw);
93 seq_printf(s, "\n\t\t\t|peak_bw=%ukBps", n->peak_bw);
94 seq_puts(s, "\"]\n");
95}
96
97static int icc_graph_show(struct seq_file *s, void *data)
98{
99 struct icc_provider *provider;
100 struct icc_node *n;
101 int cluster_index = 0;
102 int i;
103
104 seq_puts(s, "digraph {\n\trankdir = LR\n\tnode [shape = record]\n");
105 mutex_lock(&icc_lock);
106
107 /* draw providers as cluster subgraphs */
108 cluster_index = 0;
109 list_for_each_entry(provider, &icc_providers, provider_list) {
110 seq_printf(s, "\tsubgraph cluster_%d {\n", ++cluster_index);
111 if (provider->dev)
112 seq_printf(s, "\t\tlabel = \"%s\"\n",
113 dev_name(provider->dev));
114
115 /* draw nodes */
116 list_for_each_entry(n, &provider->nodes, node_list)
117 icc_graph_show_node(s, n);
118
119 /* draw internal links */
120 list_for_each_entry(n, &provider->nodes, node_list)
121 for (i = 0; i < n->num_links; ++i)
122 if (n->provider == n->links[i]->provider)
123 icc_graph_show_link(s, 2, n,
124 n->links[i]);
125
126 seq_puts(s, "\t}\n");
127 }
128
129 /* draw external links */
130 list_for_each_entry(provider, &icc_providers, provider_list)
131 list_for_each_entry(n, &provider->nodes, node_list)
132 for (i = 0; i < n->num_links; ++i)
133 if (n->provider != n->links[i]->provider)
134 icc_graph_show_link(s, 1, n,
135 n->links[i]);
136
137 mutex_unlock(&icc_lock);
138 seq_puts(s, "}");
139
140 return 0;
141}
142DEFINE_SHOW_ATTRIBUTE(icc_graph);
143
144static struct icc_node *node_find(const int id)
145{
146 return idr_find(&icc_idr, id);
147}
148
149static struct icc_path *path_init(struct device *dev, struct icc_node *dst,
150 ssize_t num_nodes)
151{
152 struct icc_node *node = dst;
153 struct icc_path *path;
154 int i;
155
156 path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL);
157 if (!path)
158 return ERR_PTR(-ENOMEM);
159
160 path->num_nodes = num_nodes;
161
162 for (i = num_nodes - 1; i >= 0; i--) {
163 node->provider->users++;
164 hlist_add_head(&path->reqs[i].req_node, &node->req_list);
165 path->reqs[i].node = node;
166 path->reqs[i].dev = dev;
167 path->reqs[i].enabled = true;
168 /* reference to previous node was saved during path traversal */
169 node = node->reverse;
170 }
171
172 return path;
173}
174
175static struct icc_path *path_find(struct device *dev, struct icc_node *src,
176 struct icc_node *dst)
177{
178 struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
179 struct icc_node *n, *node = NULL;
180 struct list_head traverse_list;
181 struct list_head edge_list;
182 struct list_head visited_list;
183 size_t i, depth = 1;
184 bool found = false;
185
186 INIT_LIST_HEAD(&traverse_list);
187 INIT_LIST_HEAD(&edge_list);
188 INIT_LIST_HEAD(&visited_list);
189
190 list_add(&src->search_list, &traverse_list);
191 src->reverse = NULL;
192
193 do {
194 list_for_each_entry_safe(node, n, &traverse_list, search_list) {
195 if (node == dst) {
196 found = true;
197 list_splice_init(&edge_list, &visited_list);
198 list_splice_init(&traverse_list, &visited_list);
199 break;
200 }
201 for (i = 0; i < node->num_links; i++) {
202 struct icc_node *tmp = node->links[i];
203
204 if (!tmp) {
205 path = ERR_PTR(-ENOENT);
206 goto out;
207 }
208
209 if (tmp->is_traversed)
210 continue;
211
212 tmp->is_traversed = true;
213 tmp->reverse = node;
214 list_add_tail(&tmp->search_list, &edge_list);
215 }
216 }
217
218 if (found)
219 break;
220
221 list_splice_init(&traverse_list, &visited_list);
222 list_splice_init(&edge_list, &traverse_list);
223
224 /* count the hops including the source */
225 depth++;
226
227 } while (!list_empty(&traverse_list));
228
229out:
230
231 /* reset the traversed state */
232 list_for_each_entry_reverse(n, &visited_list, search_list)
233 n->is_traversed = false;
234
235 if (found)
236 path = path_init(dev, dst, depth);
237
238 return path;
239}
240
241/*
242 * We want the path to honor all bandwidth requests, so the average and peak
243 * bandwidth requirements from each consumer are aggregated at each node.
244 * The aggregation is platform specific, so each platform can customize it by
245 * implementing its own aggregate() function.
246 */
247
248static int aggregate_requests(struct icc_node *node)
249{
250 struct icc_provider *p = node->provider;
251 struct icc_req *r;
252 u32 avg_bw, peak_bw;
253
254 node->avg_bw = 0;
255 node->peak_bw = 0;
256
257 if (p->pre_aggregate)
258 p->pre_aggregate(node);
259
260 hlist_for_each_entry(r, &node->req_list, req_node) {
261 if (r->enabled) {
262 avg_bw = r->avg_bw;
263 peak_bw = r->peak_bw;
264 } else {
265 avg_bw = 0;
266 peak_bw = 0;
267 }
268 p->aggregate(node, r->tag, avg_bw, peak_bw,
269 &node->avg_bw, &node->peak_bw);
270 }
271
272 return 0;
273}
274
275static int apply_constraints(struct icc_path *path)
276{
277 struct icc_node *next, *prev = NULL;
278 struct icc_provider *p;
279 int ret = -EINVAL;
280 int i;
281
282 for (i = 0; i < path->num_nodes; i++) {
283 next = path->reqs[i].node;
284 p = next->provider;
285
286 /* both endpoints should be valid master-slave pairs */
287 if (!prev || (p != prev->provider && !p->inter_set)) {
288 prev = next;
289 continue;
290 }
291
292 /* set the constraints */
293 ret = p->set(prev, next);
294 if (ret)
295 goto out;
296
297 prev = next;
298 }
299out:
300 return ret;
301}
302
303int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
304 u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
305{
306 *agg_avg += avg_bw;
307 *agg_peak = max(*agg_peak, peak_bw);
308
309 return 0;
310}
311EXPORT_SYMBOL_GPL(icc_std_aggregate);
312
313/* of_icc_xlate_onecell() - Translate function using a single index.
314 * @spec: OF phandle args to map into an interconnect node.
315 * @data: private data (pointer to struct icc_onecell_data)
316 *
317 * This is a generic translate function that can be used to model simple
318 * interconnect providers that have one device tree node and provide
319 * multiple interconnect nodes. A single cell is used as an index into
320 * an array of icc nodes specified in the icc_onecell_data struct when
321 * registering the provider.
322 */
323struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec,
324 void *data)
325{
326 struct icc_onecell_data *icc_data = data;
327 unsigned int idx = spec->args[0];
328
329 if (idx >= icc_data->num_nodes) {
330 pr_err("%s: invalid index %u\n", __func__, idx);
331 return ERR_PTR(-EINVAL);
332 }
333
334 return icc_data->nodes[idx];
335}
336EXPORT_SYMBOL_GPL(of_icc_xlate_onecell);
337
338/**
339 * of_icc_get_from_provider() - Look-up interconnect node
340 * @spec: OF phandle args to use for look-up
341 *
342 * Looks for interconnect provider under the node specified by @spec and if
343 * found, uses xlate function of the provider to map phandle args to node.
344 *
345 * Returns a valid pointer to struct icc_node on success or ERR_PTR()
346 * on failure.
347 */
348struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec)
349{
350 struct icc_node *node = ERR_PTR(-EPROBE_DEFER);
351 struct icc_provider *provider;
352
353 if (!spec)
354 return ERR_PTR(-EINVAL);
355
356 mutex_lock(&icc_lock);
357 list_for_each_entry(provider, &icc_providers, provider_list) {
358 if (provider->dev->of_node == spec->np)
359 node = provider->xlate(spec, provider->data);
360 if (!IS_ERR(node))
361 break;
362 }
363 mutex_unlock(&icc_lock);
364
365 return node;
366}
367EXPORT_SYMBOL_GPL(of_icc_get_from_provider);
368
369static void devm_icc_release(struct device *dev, void *res)
370{
371 icc_put(*(struct icc_path **)res);
372}
373
374struct icc_path *devm_of_icc_get(struct device *dev, const char *name)
375{
376 struct icc_path **ptr, *path;
377
378 ptr = devres_alloc(devm_icc_release, sizeof(**ptr), GFP_KERNEL);
379 if (!ptr)
380 return ERR_PTR(-ENOMEM);
381
382 path = of_icc_get(dev, name);
383 if (!IS_ERR(path)) {
384 *ptr = path;
385 devres_add(dev, ptr);
386 } else {
387 devres_free(ptr);
388 }
389
390 return path;
391}
392EXPORT_SYMBOL_GPL(devm_of_icc_get);
393
394/**
395 * of_icc_get_by_index() - get a path handle from a DT node based on index
396 * @dev: device pointer for the consumer device
397 * @idx: interconnect path index
398 *
399 * This function will search for a path between two endpoints and return an
400 * icc_path handle on success. Use icc_put() to release constraints when they
401 * are not needed anymore.
402 * If the interconnect API is disabled, NULL is returned and the consumer
403 * drivers will still build. Drivers are free to handle this specifically,
404 * but they don't have to.
405 *
406 * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
407 * when the API is disabled or the "interconnects" DT property is missing.
408 */
409struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
410{
411 struct icc_path *path;
412 struct icc_node *src_node, *dst_node;
413 struct device_node *np;
414 struct of_phandle_args src_args, dst_args;
415 int ret;
416
417 if (!dev || !dev->of_node)
418 return ERR_PTR(-ENODEV);
419
420 np = dev->of_node;
421
422 /*
423 * When the consumer DT node do not have "interconnects" property
424 * return a NULL path to skip setting constraints.
425 */
426 if (!of_find_property(np, "interconnects", NULL))
427 return NULL;
428
429 /*
430 * We use a combination of phandle and specifier for endpoint. For now
431 * lets support only global ids and extend this in the future if needed
432 * without breaking DT compatibility.
433 */
434 ret = of_parse_phandle_with_args(np, "interconnects",
435 "#interconnect-cells", idx * 2,
436 &src_args);
437 if (ret)
438 return ERR_PTR(ret);
439
440 of_node_put(src_args.np);
441
442 ret = of_parse_phandle_with_args(np, "interconnects",
443 "#interconnect-cells", idx * 2 + 1,
444 &dst_args);
445 if (ret)
446 return ERR_PTR(ret);
447
448 of_node_put(dst_args.np);
449
450 src_node = of_icc_get_from_provider(&src_args);
451
452 if (IS_ERR(src_node)) {
453 if (PTR_ERR(src_node) != -EPROBE_DEFER)
454 dev_err(dev, "error finding src node: %ld\n",
455 PTR_ERR(src_node));
456 return ERR_CAST(src_node);
457 }
458
459 dst_node = of_icc_get_from_provider(&dst_args);
460
461 if (IS_ERR(dst_node)) {
462 if (PTR_ERR(dst_node) != -EPROBE_DEFER)
463 dev_err(dev, "error finding dst node: %ld\n",
464 PTR_ERR(dst_node));
465 return ERR_CAST(dst_node);
466 }
467
468 mutex_lock(&icc_lock);
469 path = path_find(dev, src_node, dst_node);
470 mutex_unlock(&icc_lock);
471 if (IS_ERR(path)) {
472 dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
473 return path;
474 }
475
476 path->name = kasprintf(GFP_KERNEL, "%s-%s",
477 src_node->name, dst_node->name);
478 if (!path->name) {
479 kfree(path);
480 return ERR_PTR(-ENOMEM);
481 }
482
483 return path;
484}
485EXPORT_SYMBOL_GPL(of_icc_get_by_index);
486
487/**
488 * of_icc_get() - get a path handle from a DT node based on name
489 * @dev: device pointer for the consumer device
490 * @name: interconnect path name
491 *
492 * This function will search for a path between two endpoints and return an
493 * icc_path handle on success. Use icc_put() to release constraints when they
494 * are not needed anymore.
495 * If the interconnect API is disabled, NULL is returned and the consumer
496 * drivers will still build. Drivers are free to handle this specifically,
497 * but they don't have to.
498 *
499 * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
500 * when the API is disabled or the "interconnects" DT property is missing.
501 */
502struct icc_path *of_icc_get(struct device *dev, const char *name)
503{
504 struct device_node *np;
505 int idx = 0;
506
507 if (!dev || !dev->of_node)
508 return ERR_PTR(-ENODEV);
509
510 np = dev->of_node;
511
512 /*
513 * When the consumer DT node do not have "interconnects" property
514 * return a NULL path to skip setting constraints.
515 */
516 if (!of_find_property(np, "interconnects", NULL))
517 return NULL;
518
519 /*
520 * We use a combination of phandle and specifier for endpoint. For now
521 * lets support only global ids and extend this in the future if needed
522 * without breaking DT compatibility.
523 */
524 if (name) {
525 idx = of_property_match_string(np, "interconnect-names", name);
526 if (idx < 0)
527 return ERR_PTR(idx);
528 }
529
530 return of_icc_get_by_index(dev, idx);
531}
532EXPORT_SYMBOL_GPL(of_icc_get);
533
534/**
535 * icc_set_tag() - set an optional tag on a path
536 * @path: the path we want to tag
537 * @tag: the tag value
538 *
539 * This function allows consumers to append a tag to the requests associated
540 * with a path, so that a different aggregation could be done based on this tag.
541 */
542void icc_set_tag(struct icc_path *path, u32 tag)
543{
544 int i;
545
546 if (!path)
547 return;
548
549 mutex_lock(&icc_lock);
550
551 for (i = 0; i < path->num_nodes; i++)
552 path->reqs[i].tag = tag;
553
554 mutex_unlock(&icc_lock);
555}
556EXPORT_SYMBOL_GPL(icc_set_tag);
557
558/**
559 * icc_get_name() - Get name of the icc path
560 * @path: reference to the path returned by icc_get()
561 *
562 * This function is used by an interconnect consumer to get the name of the icc
563 * path.
564 *
565 * Returns a valid pointer on success, or NULL otherwise.
566 */
567const char *icc_get_name(struct icc_path *path)
568{
569 if (!path)
570 return NULL;
571
572 return path->name;
573}
574EXPORT_SYMBOL_GPL(icc_get_name);
575
576/**
577 * icc_set_bw() - set bandwidth constraints on an interconnect path
578 * @path: reference to the path returned by icc_get()
579 * @avg_bw: average bandwidth in kilobytes per second
580 * @peak_bw: peak bandwidth in kilobytes per second
581 *
582 * This function is used by an interconnect consumer to express its own needs
583 * in terms of bandwidth for a previously requested path between two endpoints.
584 * The requests are aggregated and each node is updated accordingly. The entire
585 * path is locked by a mutex to ensure that the set() is completed.
586 * The @path can be NULL when the "interconnects" DT properties is missing,
587 * which will mean that no constraints will be set.
588 *
589 * Returns 0 on success, or an appropriate error code otherwise.
590 */
591int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
592{
593 struct icc_node *node;
594 u32 old_avg, old_peak;
595 size_t i;
596 int ret;
597
598 if (!path)
599 return 0;
600
601 if (WARN_ON(IS_ERR(path) || !path->num_nodes))
602 return -EINVAL;
603
604 mutex_lock(&icc_lock);
605
606 old_avg = path->reqs[0].avg_bw;
607 old_peak = path->reqs[0].peak_bw;
608
609 for (i = 0; i < path->num_nodes; i++) {
610 node = path->reqs[i].node;
611
612 /* update the consumer request for this path */
613 path->reqs[i].avg_bw = avg_bw;
614 path->reqs[i].peak_bw = peak_bw;
615
616 /* aggregate requests for this node */
617 aggregate_requests(node);
618
619 trace_icc_set_bw(path, node, i, avg_bw, peak_bw);
620 }
621
622 ret = apply_constraints(path);
623 if (ret) {
624 pr_debug("interconnect: error applying constraints (%d)\n",
625 ret);
626
627 for (i = 0; i < path->num_nodes; i++) {
628 node = path->reqs[i].node;
629 path->reqs[i].avg_bw = old_avg;
630 path->reqs[i].peak_bw = old_peak;
631 aggregate_requests(node);
632 }
633 apply_constraints(path);
634 }
635
636 mutex_unlock(&icc_lock);
637
638 trace_icc_set_bw_end(path, ret);
639
640 return ret;
641}
642EXPORT_SYMBOL_GPL(icc_set_bw);
643
644static int __icc_enable(struct icc_path *path, bool enable)
645{
646 int i;
647
648 if (!path)
649 return 0;
650
651 if (WARN_ON(IS_ERR(path) || !path->num_nodes))
652 return -EINVAL;
653
654 mutex_lock(&icc_lock);
655
656 for (i = 0; i < path->num_nodes; i++)
657 path->reqs[i].enabled = enable;
658
659 mutex_unlock(&icc_lock);
660
661 return icc_set_bw(path, path->reqs[0].avg_bw,
662 path->reqs[0].peak_bw);
663}
664
665int icc_enable(struct icc_path *path)
666{
667 return __icc_enable(path, true);
668}
669EXPORT_SYMBOL_GPL(icc_enable);
670
671int icc_disable(struct icc_path *path)
672{
673 return __icc_enable(path, false);
674}
675EXPORT_SYMBOL_GPL(icc_disable);
676
677/**
678 * icc_get() - return a handle for path between two endpoints
679 * @dev: the device requesting the path
680 * @src_id: source device port id
681 * @dst_id: destination device port id
682 *
683 * This function will search for a path between two endpoints and return an
684 * icc_path handle on success. Use icc_put() to release
685 * constraints when they are not needed anymore.
686 * If the interconnect API is disabled, NULL is returned and the consumer
687 * drivers will still build. Drivers are free to handle this specifically,
688 * but they don't have to.
689 *
690 * Return: icc_path pointer on success, ERR_PTR() on error or NULL if the
691 * interconnect API is disabled.
692 */
693struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id)
694{
695 struct icc_node *src, *dst;
696 struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
697
698 mutex_lock(&icc_lock);
699
700 src = node_find(src_id);
701 if (!src)
702 goto out;
703
704 dst = node_find(dst_id);
705 if (!dst)
706 goto out;
707
708 path = path_find(dev, src, dst);
709 if (IS_ERR(path)) {
710 dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
711 goto out;
712 }
713
714 path->name = kasprintf(GFP_KERNEL, "%s-%s", src->name, dst->name);
715 if (!path->name) {
716 kfree(path);
717 path = ERR_PTR(-ENOMEM);
718 }
719out:
720 mutex_unlock(&icc_lock);
721 return path;
722}
723EXPORT_SYMBOL_GPL(icc_get);
724
725/**
726 * icc_put() - release the reference to the icc_path
727 * @path: interconnect path
728 *
729 * Use this function to release the constraints on a path when the path is
730 * no longer needed. The constraints will be re-aggregated.
731 */
732void icc_put(struct icc_path *path)
733{
734 struct icc_node *node;
735 size_t i;
736 int ret;
737
738 if (!path || WARN_ON(IS_ERR(path)))
739 return;
740
741 ret = icc_set_bw(path, 0, 0);
742 if (ret)
743 pr_err("%s: error (%d)\n", __func__, ret);
744
745 mutex_lock(&icc_lock);
746 for (i = 0; i < path->num_nodes; i++) {
747 node = path->reqs[i].node;
748 hlist_del(&path->reqs[i].req_node);
749 if (!WARN_ON(!node->provider->users))
750 node->provider->users--;
751 }
752 mutex_unlock(&icc_lock);
753
754 kfree_const(path->name);
755 kfree(path);
756}
757EXPORT_SYMBOL_GPL(icc_put);
758
759static struct icc_node *icc_node_create_nolock(int id)
760{
761 struct icc_node *node;
762
763 /* check if node already exists */
764 node = node_find(id);
765 if (node)
766 return node;
767
768 node = kzalloc(sizeof(*node), GFP_KERNEL);
769 if (!node)
770 return ERR_PTR(-ENOMEM);
771
772 id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL);
773 if (id < 0) {
774 WARN(1, "%s: couldn't get idr\n", __func__);
775 kfree(node);
776 return ERR_PTR(id);
777 }
778
779 node->id = id;
780
781 return node;
782}
783
784/**
785 * icc_node_create() - create a node
786 * @id: node id
787 *
788 * Return: icc_node pointer on success, or ERR_PTR() on error
789 */
790struct icc_node *icc_node_create(int id)
791{
792 struct icc_node *node;
793
794 mutex_lock(&icc_lock);
795
796 node = icc_node_create_nolock(id);
797
798 mutex_unlock(&icc_lock);
799
800 return node;
801}
802EXPORT_SYMBOL_GPL(icc_node_create);
803
804/**
805 * icc_node_destroy() - destroy a node
806 * @id: node id
807 */
808void icc_node_destroy(int id)
809{
810 struct icc_node *node;
811
812 mutex_lock(&icc_lock);
813
814 node = node_find(id);
815 if (node) {
816 idr_remove(&icc_idr, node->id);
817 WARN_ON(!hlist_empty(&node->req_list));
818 }
819
820 mutex_unlock(&icc_lock);
821
822 kfree(node);
823}
824EXPORT_SYMBOL_GPL(icc_node_destroy);
825
826/**
827 * icc_link_create() - create a link between two nodes
828 * @node: source node id
829 * @dst_id: destination node id
830 *
831 * Create a link between two nodes. The nodes might belong to different
832 * interconnect providers and the @dst_id node might not exist (if the
833 * provider driver has not probed yet). So just create the @dst_id node
834 * and when the actual provider driver is probed, the rest of the node
835 * data is filled.
836 *
837 * Return: 0 on success, or an error code otherwise
838 */
839int icc_link_create(struct icc_node *node, const int dst_id)
840{
841 struct icc_node *dst;
842 struct icc_node **new;
843 int ret = 0;
844
845 if (!node->provider)
846 return -EINVAL;
847
848 mutex_lock(&icc_lock);
849
850 dst = node_find(dst_id);
851 if (!dst) {
852 dst = icc_node_create_nolock(dst_id);
853
854 if (IS_ERR(dst)) {
855 ret = PTR_ERR(dst);
856 goto out;
857 }
858 }
859
860 new = krealloc(node->links,
861 (node->num_links + 1) * sizeof(*node->links),
862 GFP_KERNEL);
863 if (!new) {
864 ret = -ENOMEM;
865 goto out;
866 }
867
868 node->links = new;
869 node->links[node->num_links++] = dst;
870
871out:
872 mutex_unlock(&icc_lock);
873
874 return ret;
875}
876EXPORT_SYMBOL_GPL(icc_link_create);
877
878/**
879 * icc_link_destroy() - destroy a link between two nodes
880 * @src: pointer to source node
881 * @dst: pointer to destination node
882 *
883 * Return: 0 on success, or an error code otherwise
884 */
885int icc_link_destroy(struct icc_node *src, struct icc_node *dst)
886{
887 struct icc_node **new;
888 size_t slot;
889 int ret = 0;
890
891 if (IS_ERR_OR_NULL(src))
892 return -EINVAL;
893
894 if (IS_ERR_OR_NULL(dst))
895 return -EINVAL;
896
897 mutex_lock(&icc_lock);
898
899 for (slot = 0; slot < src->num_links; slot++)
900 if (src->links[slot] == dst)
901 break;
902
903 if (WARN_ON(slot == src->num_links)) {
904 ret = -ENXIO;
905 goto out;
906 }
907
908 src->links[slot] = src->links[--src->num_links];
909
910 new = krealloc(src->links, src->num_links * sizeof(*src->links),
911 GFP_KERNEL);
912 if (new)
913 src->links = new;
914
915out:
916 mutex_unlock(&icc_lock);
917
918 return ret;
919}
920EXPORT_SYMBOL_GPL(icc_link_destroy);
921
922/**
923 * icc_node_add() - add interconnect node to interconnect provider
924 * @node: pointer to the interconnect node
925 * @provider: pointer to the interconnect provider
926 */
927void icc_node_add(struct icc_node *node, struct icc_provider *provider)
928{
929 mutex_lock(&icc_lock);
930
931 node->provider = provider;
932 list_add_tail(&node->node_list, &provider->nodes);
933
934 mutex_unlock(&icc_lock);
935}
936EXPORT_SYMBOL_GPL(icc_node_add);
937
938/**
939 * icc_node_del() - delete interconnect node from interconnect provider
940 * @node: pointer to the interconnect node
941 */
942void icc_node_del(struct icc_node *node)
943{
944 mutex_lock(&icc_lock);
945
946 list_del(&node->node_list);
947
948 mutex_unlock(&icc_lock);
949}
950EXPORT_SYMBOL_GPL(icc_node_del);
951
952/**
953 * icc_nodes_remove() - remove all previously added nodes from provider
954 * @provider: the interconnect provider we are removing nodes from
955 *
956 * Return: 0 on success, or an error code otherwise
957 */
958int icc_nodes_remove(struct icc_provider *provider)
959{
960 struct icc_node *n, *tmp;
961
962 if (WARN_ON(IS_ERR_OR_NULL(provider)))
963 return -EINVAL;
964
965 list_for_each_entry_safe_reverse(n, tmp, &provider->nodes, node_list) {
966 icc_node_del(n);
967 icc_node_destroy(n->id);
968 }
969
970 return 0;
971}
972EXPORT_SYMBOL_GPL(icc_nodes_remove);
973
974/**
975 * icc_provider_add() - add a new interconnect provider
976 * @provider: the interconnect provider that will be added into topology
977 *
978 * Return: 0 on success, or an error code otherwise
979 */
980int icc_provider_add(struct icc_provider *provider)
981{
982 if (WARN_ON(!provider->set))
983 return -EINVAL;
984 if (WARN_ON(!provider->xlate))
985 return -EINVAL;
986
987 mutex_lock(&icc_lock);
988
989 INIT_LIST_HEAD(&provider->nodes);
990 list_add_tail(&provider->provider_list, &icc_providers);
991
992 mutex_unlock(&icc_lock);
993
994 dev_dbg(provider->dev, "interconnect provider added to topology\n");
995
996 return 0;
997}
998EXPORT_SYMBOL_GPL(icc_provider_add);
999
1000/**
1001 * icc_provider_del() - delete previously added interconnect provider
1002 * @provider: the interconnect provider that will be removed from topology
1003 *
1004 * Return: 0 on success, or an error code otherwise
1005 */
1006int icc_provider_del(struct icc_provider *provider)
1007{
1008 mutex_lock(&icc_lock);
1009 if (provider->users) {
1010 pr_warn("interconnect provider still has %d users\n",
1011 provider->users);
1012 mutex_unlock(&icc_lock);
1013 return -EBUSY;
1014 }
1015
1016 if (!list_empty(&provider->nodes)) {
1017 pr_warn("interconnect provider still has nodes\n");
1018 mutex_unlock(&icc_lock);
1019 return -EBUSY;
1020 }
1021
1022 list_del(&provider->provider_list);
1023 mutex_unlock(&icc_lock);
1024
1025 return 0;
1026}
1027EXPORT_SYMBOL_GPL(icc_provider_del);
1028
1029static int __init icc_init(void)
1030{
1031 icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
1032 debugfs_create_file("interconnect_summary", 0444,
1033 icc_debugfs_dir, NULL, &icc_summary_fops);
1034 debugfs_create_file("interconnect_graph", 0444,
1035 icc_debugfs_dir, NULL, &icc_graph_fops);
1036 return 0;
1037}
1038
1039device_initcall(icc_init);
1040
1041MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
1042MODULE_DESCRIPTION("Interconnect Driver Core");
1043MODULE_LICENSE("GPL v2");