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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/mutex.h>
  17#include <linux/slab.h>
  18#include <linux/of.h>
  19#include <linux/overflow.h>
  20
  21#include "internal.h"
  22
  23#define CREATE_TRACE_POINTS
  24#include "trace.h"
  25
  26static DEFINE_IDR(icc_idr);
  27static LIST_HEAD(icc_providers);
  28static int providers_count;
  29static bool synced_state;
  30static DEFINE_MUTEX(icc_lock);
  31static DEFINE_MUTEX(icc_bw_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_node *node_find_by_name(const char *name)
 152{
 153	struct icc_provider *provider;
 154	struct icc_node *n;
 155
 156	list_for_each_entry(provider, &icc_providers, provider_list) {
 157		list_for_each_entry(n, &provider->nodes, node_list) {
 158			if (!strcmp(n->name, name))
 159				return n;
 160		}
 161	}
 162
 163	return NULL;
 164}
 165
 166static struct icc_path *path_init(struct device *dev, struct icc_node *dst,
 167				  ssize_t num_nodes)
 168{
 169	struct icc_node *node = dst;
 170	struct icc_path *path;
 171	int i;
 172
 173	path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL);
 174	if (!path)
 175		return ERR_PTR(-ENOMEM);
 176
 177	path->num_nodes = num_nodes;
 178
 179	mutex_lock(&icc_bw_lock);
 180
 181	for (i = num_nodes - 1; i >= 0; i--) {
 182		node->provider->users++;
 183		hlist_add_head(&path->reqs[i].req_node, &node->req_list);
 184		path->reqs[i].node = node;
 185		path->reqs[i].dev = dev;
 186		path->reqs[i].enabled = true;
 187		/* reference to previous node was saved during path traversal */
 188		node = node->reverse;
 189	}
 190
 191	mutex_unlock(&icc_bw_lock);
 192
 193	return path;
 194}
 195
 196static struct icc_path *path_find(struct device *dev, struct icc_node *src,
 197				  struct icc_node *dst)
 198{
 199	struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
 200	struct icc_node *n, *node = NULL;
 201	struct list_head traverse_list;
 202	struct list_head edge_list;
 203	struct list_head visited_list;
 204	size_t i, depth = 1;
 205	bool found = false;
 206
 207	INIT_LIST_HEAD(&traverse_list);
 208	INIT_LIST_HEAD(&edge_list);
 209	INIT_LIST_HEAD(&visited_list);
 210
 211	list_add(&src->search_list, &traverse_list);
 212	src->reverse = NULL;
 213
 214	do {
 215		list_for_each_entry_safe(node, n, &traverse_list, search_list) {
 216			if (node == dst) {
 217				found = true;
 218				list_splice_init(&edge_list, &visited_list);
 219				list_splice_init(&traverse_list, &visited_list);
 220				break;
 221			}
 222			for (i = 0; i < node->num_links; i++) {
 223				struct icc_node *tmp = node->links[i];
 224
 225				if (!tmp) {
 226					path = ERR_PTR(-ENOENT);
 227					goto out;
 228				}
 229
 230				if (tmp->is_traversed)
 231					continue;
 232
 233				tmp->is_traversed = true;
 234				tmp->reverse = node;
 235				list_add_tail(&tmp->search_list, &edge_list);
 236			}
 237		}
 238
 239		if (found)
 240			break;
 241
 242		list_splice_init(&traverse_list, &visited_list);
 243		list_splice_init(&edge_list, &traverse_list);
 244
 245		/* count the hops including the source */
 246		depth++;
 247
 248	} while (!list_empty(&traverse_list));
 249
 250out:
 251
 252	/* reset the traversed state */
 253	list_for_each_entry_reverse(n, &visited_list, search_list)
 254		n->is_traversed = false;
 255
 256	if (found)
 257		path = path_init(dev, dst, depth);
 258
 259	return path;
 260}
 261
 262/*
 263 * We want the path to honor all bandwidth requests, so the average and peak
 264 * bandwidth requirements from each consumer are aggregated at each node.
 265 * The aggregation is platform specific, so each platform can customize it by
 266 * implementing its own aggregate() function.
 267 */
 268
 269static int aggregate_requests(struct icc_node *node)
 270{
 271	struct icc_provider *p = node->provider;
 272	struct icc_req *r;
 273	u32 avg_bw, peak_bw;
 274
 275	node->avg_bw = 0;
 276	node->peak_bw = 0;
 277
 278	if (p->pre_aggregate)
 279		p->pre_aggregate(node);
 280
 281	hlist_for_each_entry(r, &node->req_list, req_node) {
 282		if (r->enabled) {
 283			avg_bw = r->avg_bw;
 284			peak_bw = r->peak_bw;
 285		} else {
 286			avg_bw = 0;
 287			peak_bw = 0;
 288		}
 289		p->aggregate(node, r->tag, avg_bw, peak_bw,
 290			     &node->avg_bw, &node->peak_bw);
 291
 292		/* during boot use the initial bandwidth as a floor value */
 293		if (!synced_state) {
 294			node->avg_bw = max(node->avg_bw, node->init_avg);
 295			node->peak_bw = max(node->peak_bw, node->init_peak);
 296		}
 297	}
 298
 299	return 0;
 300}
 301
 302static int apply_constraints(struct icc_path *path)
 303{
 304	struct icc_node *next, *prev = NULL;
 305	struct icc_provider *p;
 306	int ret = -EINVAL;
 307	int i;
 308
 309	for (i = 0; i < path->num_nodes; i++) {
 310		next = path->reqs[i].node;
 311		p = next->provider;
 312
 313		/* both endpoints should be valid master-slave pairs */
 314		if (!prev || (p != prev->provider && !p->inter_set)) {
 315			prev = next;
 316			continue;
 317		}
 318
 319		/* set the constraints */
 320		ret = p->set(prev, next);
 321		if (ret)
 322			goto out;
 323
 324		prev = next;
 325	}
 326out:
 327	return ret;
 328}
 329
 330int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
 331		      u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
 332{
 333	*agg_avg += avg_bw;
 334	*agg_peak = max(*agg_peak, peak_bw);
 335
 336	return 0;
 337}
 338EXPORT_SYMBOL_GPL(icc_std_aggregate);
 339
 340/* of_icc_xlate_onecell() - Translate function using a single index.
 341 * @spec: OF phandle args to map into an interconnect node.
 342 * @data: private data (pointer to struct icc_onecell_data)
 343 *
 344 * This is a generic translate function that can be used to model simple
 345 * interconnect providers that have one device tree node and provide
 346 * multiple interconnect nodes. A single cell is used as an index into
 347 * an array of icc nodes specified in the icc_onecell_data struct when
 348 * registering the provider.
 349 */
 350struct icc_node *of_icc_xlate_onecell(const struct of_phandle_args *spec,
 351				      void *data)
 352{
 353	struct icc_onecell_data *icc_data = data;
 354	unsigned int idx = spec->args[0];
 355
 356	if (idx >= icc_data->num_nodes) {
 357		pr_err("%s: invalid index %u\n", __func__, idx);
 358		return ERR_PTR(-EINVAL);
 359	}
 360
 361	return icc_data->nodes[idx];
 362}
 363EXPORT_SYMBOL_GPL(of_icc_xlate_onecell);
 364
 365/**
 366 * of_icc_get_from_provider() - Look-up interconnect node
 367 * @spec: OF phandle args to use for look-up
 368 *
 369 * Looks for interconnect provider under the node specified by @spec and if
 370 * found, uses xlate function of the provider to map phandle args to node.
 371 *
 372 * Returns a valid pointer to struct icc_node_data on success or ERR_PTR()
 373 * on failure.
 374 */
 375struct icc_node_data *of_icc_get_from_provider(const struct of_phandle_args *spec)
 376{
 377	struct icc_node *node = ERR_PTR(-EPROBE_DEFER);
 378	struct icc_node_data *data = NULL;
 379	struct icc_provider *provider;
 380
 381	if (!spec)
 382		return ERR_PTR(-EINVAL);
 383
 384	mutex_lock(&icc_lock);
 385	list_for_each_entry(provider, &icc_providers, provider_list) {
 386		if (provider->dev->of_node == spec->np) {
 387			if (provider->xlate_extended) {
 388				data = provider->xlate_extended(spec, provider->data);
 389				if (!IS_ERR(data)) {
 390					node = data->node;
 391					break;
 392				}
 393			} else {
 394				node = provider->xlate(spec, provider->data);
 395				if (!IS_ERR(node))
 396					break;
 397			}
 398		}
 399	}
 400	mutex_unlock(&icc_lock);
 401
 402	if (!node)
 403		return ERR_PTR(-EINVAL);
 404
 405	if (IS_ERR(node))
 406		return ERR_CAST(node);
 407
 408	if (!data) {
 409		data = kzalloc(sizeof(*data), GFP_KERNEL);
 410		if (!data)
 411			return ERR_PTR(-ENOMEM);
 412		data->node = node;
 413	}
 414
 415	return data;
 416}
 417EXPORT_SYMBOL_GPL(of_icc_get_from_provider);
 418
 419static void devm_icc_release(struct device *dev, void *res)
 420{
 421	icc_put(*(struct icc_path **)res);
 422}
 423
 424struct icc_path *devm_of_icc_get(struct device *dev, const char *name)
 425{
 426	struct icc_path **ptr, *path;
 427
 428	ptr = devres_alloc(devm_icc_release, sizeof(*ptr), GFP_KERNEL);
 429	if (!ptr)
 430		return ERR_PTR(-ENOMEM);
 431
 432	path = of_icc_get(dev, name);
 433	if (!IS_ERR(path)) {
 434		*ptr = path;
 435		devres_add(dev, ptr);
 436	} else {
 437		devres_free(ptr);
 438	}
 439
 440	return path;
 441}
 442EXPORT_SYMBOL_GPL(devm_of_icc_get);
 443
 444/**
 445 * of_icc_get_by_index() - get a path handle from a DT node based on index
 446 * @dev: device pointer for the consumer device
 447 * @idx: interconnect path index
 448 *
 449 * This function will search for a path between two endpoints and return an
 450 * icc_path handle on success. Use icc_put() to release constraints when they
 451 * are not needed anymore.
 452 * If the interconnect API is disabled, NULL is returned and the consumer
 453 * drivers will still build. Drivers are free to handle this specifically,
 454 * but they don't have to.
 455 *
 456 * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
 457 * when the API is disabled or the "interconnects" DT property is missing.
 458 */
 459struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
 460{
 461	struct icc_path *path;
 462	struct icc_node_data *src_data, *dst_data;
 463	struct device_node *np;
 464	struct of_phandle_args src_args, dst_args;
 465	int ret;
 466
 467	if (!dev || !dev->of_node)
 468		return ERR_PTR(-ENODEV);
 469
 470	np = dev->of_node;
 471
 472	/*
 473	 * When the consumer DT node do not have "interconnects" property
 474	 * return a NULL path to skip setting constraints.
 475	 */
 476	if (!of_property_present(np, "interconnects"))
 477		return NULL;
 478
 479	/*
 480	 * We use a combination of phandle and specifier for endpoint. For now
 481	 * lets support only global ids and extend this in the future if needed
 482	 * without breaking DT compatibility.
 483	 */
 484	ret = of_parse_phandle_with_args(np, "interconnects",
 485					 "#interconnect-cells", idx * 2,
 486					 &src_args);
 487	if (ret)
 488		return ERR_PTR(ret);
 489
 490	of_node_put(src_args.np);
 491
 492	ret = of_parse_phandle_with_args(np, "interconnects",
 493					 "#interconnect-cells", idx * 2 + 1,
 494					 &dst_args);
 495	if (ret)
 496		return ERR_PTR(ret);
 497
 498	of_node_put(dst_args.np);
 499
 500	src_data = of_icc_get_from_provider(&src_args);
 501
 502	if (IS_ERR(src_data)) {
 503		dev_err_probe(dev, PTR_ERR(src_data), "error finding src node\n");
 504		return ERR_CAST(src_data);
 505	}
 506
 507	dst_data = of_icc_get_from_provider(&dst_args);
 508
 509	if (IS_ERR(dst_data)) {
 510		dev_err_probe(dev, PTR_ERR(dst_data), "error finding dst node\n");
 511		kfree(src_data);
 512		return ERR_CAST(dst_data);
 513	}
 514
 515	mutex_lock(&icc_lock);
 516	path = path_find(dev, src_data->node, dst_data->node);
 517	mutex_unlock(&icc_lock);
 518	if (IS_ERR(path)) {
 519		dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
 520		goto free_icc_data;
 521	}
 522
 523	if (src_data->tag && src_data->tag == dst_data->tag)
 524		icc_set_tag(path, src_data->tag);
 525
 526	path->name = kasprintf(GFP_KERNEL, "%s-%s",
 527			       src_data->node->name, dst_data->node->name);
 528	if (!path->name) {
 529		kfree(path);
 530		path = ERR_PTR(-ENOMEM);
 531	}
 532
 533free_icc_data:
 534	kfree(src_data);
 535	kfree(dst_data);
 536	return path;
 537}
 538EXPORT_SYMBOL_GPL(of_icc_get_by_index);
 539
 540/**
 541 * of_icc_get() - get a path handle from a DT node based on name
 542 * @dev: device pointer for the consumer device
 543 * @name: interconnect path name
 544 *
 545 * This function will search for a path between two endpoints and return an
 546 * icc_path handle on success. Use icc_put() to release constraints when they
 547 * are not needed anymore.
 548 * If the interconnect API is disabled, NULL is returned and the consumer
 549 * drivers will still build. Drivers are free to handle this specifically,
 550 * but they don't have to.
 551 *
 552 * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
 553 * when the API is disabled or the "interconnects" DT property is missing.
 554 */
 555struct icc_path *of_icc_get(struct device *dev, const char *name)
 556{
 557	struct device_node *np;
 558	int idx = 0;
 559
 560	if (!dev || !dev->of_node)
 561		return ERR_PTR(-ENODEV);
 562
 563	np = dev->of_node;
 564
 565	/*
 566	 * When the consumer DT node do not have "interconnects" property
 567	 * return a NULL path to skip setting constraints.
 568	 */
 569	if (!of_property_present(np, "interconnects"))
 570		return NULL;
 571
 572	/*
 573	 * We use a combination of phandle and specifier for endpoint. For now
 574	 * lets support only global ids and extend this in the future if needed
 575	 * without breaking DT compatibility.
 576	 */
 577	if (name) {
 578		idx = of_property_match_string(np, "interconnect-names", name);
 579		if (idx < 0)
 580			return ERR_PTR(idx);
 581	}
 582
 583	return of_icc_get_by_index(dev, idx);
 584}
 585EXPORT_SYMBOL_GPL(of_icc_get);
 586
 587/**
 588 * icc_get() - get a path handle between two endpoints
 589 * @dev: device pointer for the consumer device
 590 * @src: source node name
 591 * @dst: destination node name
 592 *
 593 * This function will search for a path between two endpoints and return an
 594 * icc_path handle on success. Use icc_put() to release constraints when they
 595 * are not needed anymore.
 596 *
 597 * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
 598 * when the API is disabled.
 599 */
 600struct icc_path *icc_get(struct device *dev, const char *src, const char *dst)
 601{
 602	struct icc_node *src_node, *dst_node;
 603	struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
 604
 605	mutex_lock(&icc_lock);
 606
 607	src_node = node_find_by_name(src);
 608	if (!src_node) {
 609		dev_err(dev, "%s: invalid src=%s\n", __func__, src);
 610		goto out;
 611	}
 612
 613	dst_node = node_find_by_name(dst);
 614	if (!dst_node) {
 615		dev_err(dev, "%s: invalid dst=%s\n", __func__, dst);
 616		goto out;
 617	}
 618
 619	path = path_find(dev, src_node, dst_node);
 620	if (IS_ERR(path)) {
 621		dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
 622		goto out;
 623	}
 624
 625	path->name = kasprintf(GFP_KERNEL, "%s-%s", src_node->name, dst_node->name);
 626	if (!path->name) {
 627		kfree(path);
 628		path = ERR_PTR(-ENOMEM);
 629	}
 630out:
 631	mutex_unlock(&icc_lock);
 632	return path;
 633}
 634
 635/**
 636 * icc_set_tag() - set an optional tag on a path
 637 * @path: the path we want to tag
 638 * @tag: the tag value
 639 *
 640 * This function allows consumers to append a tag to the requests associated
 641 * with a path, so that a different aggregation could be done based on this tag.
 642 */
 643void icc_set_tag(struct icc_path *path, u32 tag)
 644{
 645	int i;
 646
 647	if (!path)
 648		return;
 649
 650	mutex_lock(&icc_lock);
 651
 652	for (i = 0; i < path->num_nodes; i++)
 653		path->reqs[i].tag = tag;
 654
 655	mutex_unlock(&icc_lock);
 656}
 657EXPORT_SYMBOL_GPL(icc_set_tag);
 658
 659/**
 660 * icc_get_name() - Get name of the icc path
 661 * @path: interconnect path
 662 *
 663 * This function is used by an interconnect consumer to get the name of the icc
 664 * path.
 665 *
 666 * Returns a valid pointer on success, or NULL otherwise.
 667 */
 668const char *icc_get_name(struct icc_path *path)
 669{
 670	if (!path)
 671		return NULL;
 672
 673	return path->name;
 674}
 675EXPORT_SYMBOL_GPL(icc_get_name);
 676
 677/**
 678 * icc_set_bw() - set bandwidth constraints on an interconnect path
 679 * @path: interconnect path
 680 * @avg_bw: average bandwidth in kilobytes per second
 681 * @peak_bw: peak bandwidth in kilobytes per second
 682 *
 683 * This function is used by an interconnect consumer to express its own needs
 684 * in terms of bandwidth for a previously requested path between two endpoints.
 685 * The requests are aggregated and each node is updated accordingly. The entire
 686 * path is locked by a mutex to ensure that the set() is completed.
 687 * The @path can be NULL when the "interconnects" DT properties is missing,
 688 * which will mean that no constraints will be set.
 689 *
 690 * Returns 0 on success, or an appropriate error code otherwise.
 691 */
 692int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
 693{
 694	struct icc_node *node;
 695	u32 old_avg, old_peak;
 696	size_t i;
 697	int ret;
 698
 699	if (!path)
 700		return 0;
 701
 702	if (WARN_ON(IS_ERR(path) || !path->num_nodes))
 703		return -EINVAL;
 704
 705	mutex_lock(&icc_bw_lock);
 706
 707	old_avg = path->reqs[0].avg_bw;
 708	old_peak = path->reqs[0].peak_bw;
 709
 710	for (i = 0; i < path->num_nodes; i++) {
 711		node = path->reqs[i].node;
 712
 713		/* update the consumer request for this path */
 714		path->reqs[i].avg_bw = avg_bw;
 715		path->reqs[i].peak_bw = peak_bw;
 716
 717		/* aggregate requests for this node */
 718		aggregate_requests(node);
 719
 720		trace_icc_set_bw(path, node, i, avg_bw, peak_bw);
 721	}
 722
 723	ret = apply_constraints(path);
 724	if (ret) {
 725		pr_debug("interconnect: error applying constraints (%d)\n",
 726			 ret);
 727
 728		for (i = 0; i < path->num_nodes; i++) {
 729			node = path->reqs[i].node;
 730			path->reqs[i].avg_bw = old_avg;
 731			path->reqs[i].peak_bw = old_peak;
 732			aggregate_requests(node);
 733		}
 734		apply_constraints(path);
 735	}
 736
 737	mutex_unlock(&icc_bw_lock);
 738
 739	trace_icc_set_bw_end(path, ret);
 740
 741	return ret;
 742}
 743EXPORT_SYMBOL_GPL(icc_set_bw);
 744
 745static int __icc_enable(struct icc_path *path, bool enable)
 746{
 747	int i;
 748
 749	if (!path)
 750		return 0;
 751
 752	if (WARN_ON(IS_ERR(path) || !path->num_nodes))
 753		return -EINVAL;
 754
 755	mutex_lock(&icc_lock);
 756
 757	for (i = 0; i < path->num_nodes; i++)
 758		path->reqs[i].enabled = enable;
 759
 760	mutex_unlock(&icc_lock);
 761
 762	return icc_set_bw(path, path->reqs[0].avg_bw,
 763			  path->reqs[0].peak_bw);
 764}
 765
 766int icc_enable(struct icc_path *path)
 767{
 768	return __icc_enable(path, true);
 769}
 770EXPORT_SYMBOL_GPL(icc_enable);
 771
 772int icc_disable(struct icc_path *path)
 773{
 774	return __icc_enable(path, false);
 775}
 776EXPORT_SYMBOL_GPL(icc_disable);
 777
 778/**
 779 * icc_put() - release the reference to the icc_path
 780 * @path: interconnect path
 781 *
 782 * Use this function to release the constraints on a path when the path is
 783 * no longer needed. The constraints will be re-aggregated.
 784 */
 785void icc_put(struct icc_path *path)
 786{
 787	struct icc_node *node;
 788	size_t i;
 789	int ret;
 790
 791	if (!path || WARN_ON(IS_ERR(path)))
 792		return;
 793
 794	ret = icc_set_bw(path, 0, 0);
 795	if (ret)
 796		pr_err("%s: error (%d)\n", __func__, ret);
 797
 798	mutex_lock(&icc_lock);
 799	mutex_lock(&icc_bw_lock);
 800
 801	for (i = 0; i < path->num_nodes; i++) {
 802		node = path->reqs[i].node;
 803		hlist_del(&path->reqs[i].req_node);
 804		if (!WARN_ON(!node->provider->users))
 805			node->provider->users--;
 806	}
 807
 808	mutex_unlock(&icc_bw_lock);
 809	mutex_unlock(&icc_lock);
 810
 811	kfree_const(path->name);
 812	kfree(path);
 813}
 814EXPORT_SYMBOL_GPL(icc_put);
 815
 816static struct icc_node *icc_node_create_nolock(int id)
 817{
 818	struct icc_node *node;
 819
 820	/* check if node already exists */
 821	node = node_find(id);
 822	if (node)
 823		return node;
 824
 825	node = kzalloc(sizeof(*node), GFP_KERNEL);
 826	if (!node)
 827		return ERR_PTR(-ENOMEM);
 828
 829	id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL);
 830	if (id < 0) {
 831		WARN(1, "%s: couldn't get idr\n", __func__);
 832		kfree(node);
 833		return ERR_PTR(id);
 834	}
 835
 836	node->id = id;
 837
 838	return node;
 839}
 840
 841/**
 842 * icc_node_create() - create a node
 843 * @id: node id
 844 *
 845 * Return: icc_node pointer on success, or ERR_PTR() on error
 846 */
 847struct icc_node *icc_node_create(int id)
 848{
 849	struct icc_node *node;
 850
 851	mutex_lock(&icc_lock);
 852
 853	node = icc_node_create_nolock(id);
 854
 855	mutex_unlock(&icc_lock);
 856
 857	return node;
 858}
 859EXPORT_SYMBOL_GPL(icc_node_create);
 860
 861/**
 862 * icc_node_destroy() - destroy a node
 863 * @id: node id
 864 */
 865void icc_node_destroy(int id)
 866{
 867	struct icc_node *node;
 868
 869	mutex_lock(&icc_lock);
 870
 871	node = node_find(id);
 872	if (node) {
 873		idr_remove(&icc_idr, node->id);
 874		WARN_ON(!hlist_empty(&node->req_list));
 875	}
 876
 877	mutex_unlock(&icc_lock);
 878
 879	if (!node)
 880		return;
 881
 882	kfree(node->links);
 883	kfree(node);
 884}
 885EXPORT_SYMBOL_GPL(icc_node_destroy);
 886
 887/**
 888 * icc_link_create() - create a link between two nodes
 889 * @node: source node id
 890 * @dst_id: destination node id
 891 *
 892 * Create a link between two nodes. The nodes might belong to different
 893 * interconnect providers and the @dst_id node might not exist (if the
 894 * provider driver has not probed yet). So just create the @dst_id node
 895 * and when the actual provider driver is probed, the rest of the node
 896 * data is filled.
 897 *
 898 * Return: 0 on success, or an error code otherwise
 899 */
 900int icc_link_create(struct icc_node *node, const int dst_id)
 901{
 902	struct icc_node *dst;
 903	struct icc_node **new;
 904	int ret = 0;
 905
 906	if (!node->provider)
 907		return -EINVAL;
 908
 909	mutex_lock(&icc_lock);
 910
 911	dst = node_find(dst_id);
 912	if (!dst) {
 913		dst = icc_node_create_nolock(dst_id);
 914
 915		if (IS_ERR(dst)) {
 916			ret = PTR_ERR(dst);
 917			goto out;
 918		}
 919	}
 920
 921	new = krealloc(node->links,
 922		       (node->num_links + 1) * sizeof(*node->links),
 923		       GFP_KERNEL);
 924	if (!new) {
 925		ret = -ENOMEM;
 926		goto out;
 927	}
 928
 929	node->links = new;
 930	node->links[node->num_links++] = dst;
 931
 932out:
 933	mutex_unlock(&icc_lock);
 934
 935	return ret;
 936}
 937EXPORT_SYMBOL_GPL(icc_link_create);
 938
 939/**
 940 * icc_node_add() - add interconnect node to interconnect provider
 941 * @node: pointer to the interconnect node
 942 * @provider: pointer to the interconnect provider
 943 */
 944void icc_node_add(struct icc_node *node, struct icc_provider *provider)
 945{
 946	if (WARN_ON(node->provider))
 947		return;
 948
 949	mutex_lock(&icc_lock);
 950	mutex_lock(&icc_bw_lock);
 951
 952	node->provider = provider;
 953	list_add_tail(&node->node_list, &provider->nodes);
 954
 955	/* get the initial bandwidth values and sync them with hardware */
 956	if (provider->get_bw) {
 957		provider->get_bw(node, &node->init_avg, &node->init_peak);
 958	} else {
 959		node->init_avg = INT_MAX;
 960		node->init_peak = INT_MAX;
 961	}
 962	node->avg_bw = node->init_avg;
 963	node->peak_bw = node->init_peak;
 964
 965	if (node->avg_bw || node->peak_bw) {
 966		if (provider->pre_aggregate)
 967			provider->pre_aggregate(node);
 968
 969		if (provider->aggregate)
 970			provider->aggregate(node, 0, node->init_avg, node->init_peak,
 971					    &node->avg_bw, &node->peak_bw);
 972		if (provider->set)
 973			provider->set(node, node);
 974	}
 975
 976	node->avg_bw = 0;
 977	node->peak_bw = 0;
 978
 979	mutex_unlock(&icc_bw_lock);
 980	mutex_unlock(&icc_lock);
 981}
 982EXPORT_SYMBOL_GPL(icc_node_add);
 983
 984/**
 985 * icc_node_del() - delete interconnect node from interconnect provider
 986 * @node: pointer to the interconnect node
 987 */
 988void icc_node_del(struct icc_node *node)
 989{
 990	mutex_lock(&icc_lock);
 991
 992	list_del(&node->node_list);
 993
 994	mutex_unlock(&icc_lock);
 995}
 996EXPORT_SYMBOL_GPL(icc_node_del);
 997
 998/**
 999 * icc_nodes_remove() - remove all previously added nodes from provider
1000 * @provider: the interconnect provider we are removing nodes from
1001 *
1002 * Return: 0 on success, or an error code otherwise
1003 */
1004int icc_nodes_remove(struct icc_provider *provider)
1005{
1006	struct icc_node *n, *tmp;
1007
1008	if (WARN_ON(IS_ERR_OR_NULL(provider)))
1009		return -EINVAL;
1010
1011	list_for_each_entry_safe_reverse(n, tmp, &provider->nodes, node_list) {
1012		icc_node_del(n);
1013		icc_node_destroy(n->id);
1014	}
1015
1016	return 0;
1017}
1018EXPORT_SYMBOL_GPL(icc_nodes_remove);
1019
1020/**
1021 * icc_provider_init() - initialize a new interconnect provider
1022 * @provider: the interconnect provider to initialize
1023 *
1024 * Must be called before adding nodes to the provider.
1025 */
1026void icc_provider_init(struct icc_provider *provider)
1027{
1028	WARN_ON(!provider->set);
1029
1030	INIT_LIST_HEAD(&provider->nodes);
1031}
1032EXPORT_SYMBOL_GPL(icc_provider_init);
1033
1034/**
1035 * icc_provider_register() - register a new interconnect provider
1036 * @provider: the interconnect provider to register
1037 *
1038 * Return: 0 on success, or an error code otherwise
1039 */
1040int icc_provider_register(struct icc_provider *provider)
1041{
1042	if (WARN_ON(!provider->xlate && !provider->xlate_extended))
1043		return -EINVAL;
1044
1045	mutex_lock(&icc_lock);
1046	list_add_tail(&provider->provider_list, &icc_providers);
1047	mutex_unlock(&icc_lock);
1048
1049	dev_dbg(provider->dev, "interconnect provider registered\n");
1050
1051	return 0;
1052}
1053EXPORT_SYMBOL_GPL(icc_provider_register);
1054
1055/**
1056 * icc_provider_deregister() - deregister an interconnect provider
1057 * @provider: the interconnect provider to deregister
1058 */
1059void icc_provider_deregister(struct icc_provider *provider)
1060{
1061	mutex_lock(&icc_lock);
1062	WARN_ON(provider->users);
1063
1064	list_del(&provider->provider_list);
1065	mutex_unlock(&icc_lock);
1066}
1067EXPORT_SYMBOL_GPL(icc_provider_deregister);
1068
1069static const struct of_device_id __maybe_unused ignore_list[] = {
1070	{ .compatible = "qcom,sc7180-ipa-virt" },
1071	{ .compatible = "qcom,sc8180x-ipa-virt" },
1072	{ .compatible = "qcom,sdx55-ipa-virt" },
1073	{ .compatible = "qcom,sm8150-ipa-virt" },
1074	{ .compatible = "qcom,sm8250-ipa-virt" },
1075	{}
1076};
1077
1078static int of_count_icc_providers(struct device_node *np)
1079{
1080	struct device_node *child;
1081	int count = 0;
1082
1083	for_each_available_child_of_node(np, child) {
1084		if (of_property_read_bool(child, "#interconnect-cells") &&
1085		    likely(!of_match_node(ignore_list, child)))
1086			count++;
1087		count += of_count_icc_providers(child);
1088	}
1089
1090	return count;
1091}
1092
1093void icc_sync_state(struct device *dev)
1094{
1095	struct icc_provider *p;
1096	struct icc_node *n;
1097	static int count;
1098
1099	count++;
1100
1101	if (count < providers_count)
1102		return;
1103
1104	mutex_lock(&icc_lock);
1105	mutex_lock(&icc_bw_lock);
1106	synced_state = true;
1107	list_for_each_entry(p, &icc_providers, provider_list) {
1108		dev_dbg(p->dev, "interconnect provider is in synced state\n");
1109		list_for_each_entry(n, &p->nodes, node_list) {
1110			if (n->init_avg || n->init_peak) {
1111				n->init_avg = 0;
1112				n->init_peak = 0;
1113				aggregate_requests(n);
1114				p->set(n, n);
1115			}
1116		}
1117	}
1118	mutex_unlock(&icc_bw_lock);
1119	mutex_unlock(&icc_lock);
1120}
1121EXPORT_SYMBOL_GPL(icc_sync_state);
1122
1123static int __init icc_init(void)
1124{
1125	struct device_node *root;
1126
1127	/* Teach lockdep about lock ordering wrt. shrinker: */
1128	fs_reclaim_acquire(GFP_KERNEL);
1129	might_lock(&icc_bw_lock);
1130	fs_reclaim_release(GFP_KERNEL);
1131
1132	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
1143	icc_debugfs_client_init(icc_debugfs_dir);
1144
1145	return 0;
1146}
1147
1148device_initcall(icc_init);