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 (!node) 384 return ERR_PTR(-EINVAL); 385 386 if (IS_ERR(node)) 387 return ERR_CAST(node); 388 389 if (!data) { 390 data = kzalloc(sizeof(*data), GFP_KERNEL); 391 if (!data) 392 return ERR_PTR(-ENOMEM); 393 data->node = node; 394 } 395 396 return data; 397} 398EXPORT_SYMBOL_GPL(of_icc_get_from_provider); 399 400static void devm_icc_release(struct device *dev, void *res) 401{ 402 icc_put(*(struct icc_path **)res); 403} 404 405struct icc_path *devm_of_icc_get(struct device *dev, const char *name) 406{ 407 struct icc_path **ptr, *path; 408 409 ptr = devres_alloc(devm_icc_release, sizeof(*ptr), GFP_KERNEL); 410 if (!ptr) 411 return ERR_PTR(-ENOMEM); 412 413 path = of_icc_get(dev, name); 414 if (!IS_ERR(path)) { 415 *ptr = path; 416 devres_add(dev, ptr); 417 } else { 418 devres_free(ptr); 419 } 420 421 return path; 422} 423EXPORT_SYMBOL_GPL(devm_of_icc_get); 424 425/** 426 * of_icc_get_by_index() - get a path handle from a DT node based on index 427 * @dev: device pointer for the consumer device 428 * @idx: interconnect path index 429 * 430 * This function will search for a path between two endpoints and return an 431 * icc_path handle on success. Use icc_put() to release constraints when they 432 * are not needed anymore. 433 * If the interconnect API is disabled, NULL is returned and the consumer 434 * drivers will still build. Drivers are free to handle this specifically, 435 * but they don't have to. 436 * 437 * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned 438 * when the API is disabled or the "interconnects" DT property is missing. 439 */ 440struct icc_path *of_icc_get_by_index(struct device *dev, int idx) 441{ 442 struct icc_path *path; 443 struct icc_node_data *src_data, *dst_data; 444 struct device_node *np; 445 struct of_phandle_args src_args, dst_args; 446 int ret; 447 448 if (!dev || !dev->of_node) 449 return ERR_PTR(-ENODEV); 450 451 np = dev->of_node; 452 453 /* 454 * When the consumer DT node do not have "interconnects" property 455 * return a NULL path to skip setting constraints. 456 */ 457 if (!of_find_property(np, "interconnects", NULL)) 458 return NULL; 459 460 /* 461 * We use a combination of phandle and specifier for endpoint. For now 462 * lets support only global ids and extend this in the future if needed 463 * without breaking DT compatibility. 464 */ 465 ret = of_parse_phandle_with_args(np, "interconnects", 466 "#interconnect-cells", idx * 2, 467 &src_args); 468 if (ret) 469 return ERR_PTR(ret); 470 471 of_node_put(src_args.np); 472 473 ret = of_parse_phandle_with_args(np, "interconnects", 474 "#interconnect-cells", idx * 2 + 1, 475 &dst_args); 476 if (ret) 477 return ERR_PTR(ret); 478 479 of_node_put(dst_args.np); 480 481 src_data = of_icc_get_from_provider(&src_args); 482 483 if (IS_ERR(src_data)) { 484 dev_err_probe(dev, PTR_ERR(src_data), "error finding src node\n"); 485 return ERR_CAST(src_data); 486 } 487 488 dst_data = of_icc_get_from_provider(&dst_args); 489 490 if (IS_ERR(dst_data)) { 491 dev_err_probe(dev, PTR_ERR(dst_data), "error finding dst node\n"); 492 kfree(src_data); 493 return ERR_CAST(dst_data); 494 } 495 496 mutex_lock(&icc_lock); 497 path = path_find(dev, src_data->node, dst_data->node); 498 mutex_unlock(&icc_lock); 499 if (IS_ERR(path)) { 500 dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); 501 goto free_icc_data; 502 } 503 504 if (src_data->tag && src_data->tag == dst_data->tag) 505 icc_set_tag(path, src_data->tag); 506 507 path->name = kasprintf(GFP_KERNEL, "%s-%s", 508 src_data->node->name, dst_data->node->name); 509 if (!path->name) { 510 kfree(path); 511 path = ERR_PTR(-ENOMEM); 512 } 513 514free_icc_data: 515 kfree(src_data); 516 kfree(dst_data); 517 return path; 518} 519EXPORT_SYMBOL_GPL(of_icc_get_by_index); 520 521/** 522 * of_icc_get() - get a path handle from a DT node based on name 523 * @dev: device pointer for the consumer device 524 * @name: interconnect path name 525 * 526 * This function will search for a path between two endpoints and return an 527 * icc_path handle on success. Use icc_put() to release constraints when they 528 * are not needed anymore. 529 * If the interconnect API is disabled, NULL is returned and the consumer 530 * drivers will still build. Drivers are free to handle this specifically, 531 * but they don't have to. 532 * 533 * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned 534 * when the API is disabled or the "interconnects" DT property is missing. 535 */ 536struct icc_path *of_icc_get(struct device *dev, const char *name) 537{ 538 struct device_node *np; 539 int idx = 0; 540 541 if (!dev || !dev->of_node) 542 return ERR_PTR(-ENODEV); 543 544 np = dev->of_node; 545 546 /* 547 * When the consumer DT node do not have "interconnects" property 548 * return a NULL path to skip setting constraints. 549 */ 550 if (!of_find_property(np, "interconnects", NULL)) 551 return NULL; 552 553 /* 554 * We use a combination of phandle and specifier for endpoint. For now 555 * lets support only global ids and extend this in the future if needed 556 * without breaking DT compatibility. 557 */ 558 if (name) { 559 idx = of_property_match_string(np, "interconnect-names", name); 560 if (idx < 0) 561 return ERR_PTR(idx); 562 } 563 564 return of_icc_get_by_index(dev, idx); 565} 566EXPORT_SYMBOL_GPL(of_icc_get); 567 568/** 569 * icc_set_tag() - set an optional tag on a path 570 * @path: the path we want to tag 571 * @tag: the tag value 572 * 573 * This function allows consumers to append a tag to the requests associated 574 * with a path, so that a different aggregation could be done based on this tag. 575 */ 576void icc_set_tag(struct icc_path *path, u32 tag) 577{ 578 int i; 579 580 if (!path) 581 return; 582 583 mutex_lock(&icc_lock); 584 585 for (i = 0; i < path->num_nodes; i++) 586 path->reqs[i].tag = tag; 587 588 mutex_unlock(&icc_lock); 589} 590EXPORT_SYMBOL_GPL(icc_set_tag); 591 592/** 593 * icc_get_name() - Get name of the icc path 594 * @path: reference to the path returned by icc_get() 595 * 596 * This function is used by an interconnect consumer to get the name of the icc 597 * path. 598 * 599 * Returns a valid pointer on success, or NULL otherwise. 600 */ 601const char *icc_get_name(struct icc_path *path) 602{ 603 if (!path) 604 return NULL; 605 606 return path->name; 607} 608EXPORT_SYMBOL_GPL(icc_get_name); 609 610/** 611 * icc_set_bw() - set bandwidth constraints on an interconnect path 612 * @path: reference to the path returned by icc_get() 613 * @avg_bw: average bandwidth in kilobytes per second 614 * @peak_bw: peak bandwidth in kilobytes per second 615 * 616 * This function is used by an interconnect consumer to express its own needs 617 * in terms of bandwidth for a previously requested path between two endpoints. 618 * The requests are aggregated and each node is updated accordingly. The entire 619 * path is locked by a mutex to ensure that the set() is completed. 620 * The @path can be NULL when the "interconnects" DT properties is missing, 621 * which will mean that no constraints will be set. 622 * 623 * Returns 0 on success, or an appropriate error code otherwise. 624 */ 625int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw) 626{ 627 struct icc_node *node; 628 u32 old_avg, old_peak; 629 size_t i; 630 int ret; 631 632 if (!path) 633 return 0; 634 635 if (WARN_ON(IS_ERR(path) || !path->num_nodes)) 636 return -EINVAL; 637 638 mutex_lock(&icc_lock); 639 640 old_avg = path->reqs[0].avg_bw; 641 old_peak = path->reqs[0].peak_bw; 642 643 for (i = 0; i < path->num_nodes; i++) { 644 node = path->reqs[i].node; 645 646 /* update the consumer request for this path */ 647 path->reqs[i].avg_bw = avg_bw; 648 path->reqs[i].peak_bw = peak_bw; 649 650 /* aggregate requests for this node */ 651 aggregate_requests(node); 652 653 trace_icc_set_bw(path, node, i, avg_bw, peak_bw); 654 } 655 656 ret = apply_constraints(path); 657 if (ret) { 658 pr_debug("interconnect: error applying constraints (%d)\n", 659 ret); 660 661 for (i = 0; i < path->num_nodes; i++) { 662 node = path->reqs[i].node; 663 path->reqs[i].avg_bw = old_avg; 664 path->reqs[i].peak_bw = old_peak; 665 aggregate_requests(node); 666 } 667 apply_constraints(path); 668 } 669 670 mutex_unlock(&icc_lock); 671 672 trace_icc_set_bw_end(path, ret); 673 674 return ret; 675} 676EXPORT_SYMBOL_GPL(icc_set_bw); 677 678static int __icc_enable(struct icc_path *path, bool enable) 679{ 680 int i; 681 682 if (!path) 683 return 0; 684 685 if (WARN_ON(IS_ERR(path) || !path->num_nodes)) 686 return -EINVAL; 687 688 mutex_lock(&icc_lock); 689 690 for (i = 0; i < path->num_nodes; i++) 691 path->reqs[i].enabled = enable; 692 693 mutex_unlock(&icc_lock); 694 695 return icc_set_bw(path, path->reqs[0].avg_bw, 696 path->reqs[0].peak_bw); 697} 698 699int icc_enable(struct icc_path *path) 700{ 701 return __icc_enable(path, true); 702} 703EXPORT_SYMBOL_GPL(icc_enable); 704 705int icc_disable(struct icc_path *path) 706{ 707 return __icc_enable(path, false); 708} 709EXPORT_SYMBOL_GPL(icc_disable); 710 711/** 712 * icc_get() - return a handle for path between two endpoints 713 * @dev: the device requesting the path 714 * @src_id: source device port id 715 * @dst_id: destination device port id 716 * 717 * This function will search for a path between two endpoints and return an 718 * icc_path handle on success. Use icc_put() to release 719 * constraints when they are not needed anymore. 720 * If the interconnect API is disabled, NULL is returned and the consumer 721 * drivers will still build. Drivers are free to handle this specifically, 722 * but they don't have to. 723 * 724 * Return: icc_path pointer on success, ERR_PTR() on error or NULL if the 725 * interconnect API is disabled. 726 */ 727struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id) 728{ 729 struct icc_node *src, *dst; 730 struct icc_path *path = ERR_PTR(-EPROBE_DEFER); 731 732 mutex_lock(&icc_lock); 733 734 src = node_find(src_id); 735 if (!src) 736 goto out; 737 738 dst = node_find(dst_id); 739 if (!dst) 740 goto out; 741 742 path = path_find(dev, src, dst); 743 if (IS_ERR(path)) { 744 dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); 745 goto out; 746 } 747 748 path->name = kasprintf(GFP_KERNEL, "%s-%s", src->name, dst->name); 749 if (!path->name) { 750 kfree(path); 751 path = ERR_PTR(-ENOMEM); 752 } 753out: 754 mutex_unlock(&icc_lock); 755 return path; 756} 757EXPORT_SYMBOL_GPL(icc_get); 758 759/** 760 * icc_put() - release the reference to the icc_path 761 * @path: interconnect path 762 * 763 * Use this function to release the constraints on a path when the path is 764 * no longer needed. The constraints will be re-aggregated. 765 */ 766void icc_put(struct icc_path *path) 767{ 768 struct icc_node *node; 769 size_t i; 770 int ret; 771 772 if (!path || WARN_ON(IS_ERR(path))) 773 return; 774 775 ret = icc_set_bw(path, 0, 0); 776 if (ret) 777 pr_err("%s: error (%d)\n", __func__, ret); 778 779 mutex_lock(&icc_lock); 780 for (i = 0; i < path->num_nodes; i++) { 781 node = path->reqs[i].node; 782 hlist_del(&path->reqs[i].req_node); 783 if (!WARN_ON(!node->provider->users)) 784 node->provider->users--; 785 } 786 mutex_unlock(&icc_lock); 787 788 kfree_const(path->name); 789 kfree(path); 790} 791EXPORT_SYMBOL_GPL(icc_put); 792 793static struct icc_node *icc_node_create_nolock(int id) 794{ 795 struct icc_node *node; 796 797 /* check if node already exists */ 798 node = node_find(id); 799 if (node) 800 return node; 801 802 node = kzalloc(sizeof(*node), GFP_KERNEL); 803 if (!node) 804 return ERR_PTR(-ENOMEM); 805 806 id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL); 807 if (id < 0) { 808 WARN(1, "%s: couldn't get idr\n", __func__); 809 kfree(node); 810 return ERR_PTR(id); 811 } 812 813 node->id = id; 814 815 return node; 816} 817 818/** 819 * icc_node_create() - create a node 820 * @id: node id 821 * 822 * Return: icc_node pointer on success, or ERR_PTR() on error 823 */ 824struct icc_node *icc_node_create(int id) 825{ 826 struct icc_node *node; 827 828 mutex_lock(&icc_lock); 829 830 node = icc_node_create_nolock(id); 831 832 mutex_unlock(&icc_lock); 833 834 return node; 835} 836EXPORT_SYMBOL_GPL(icc_node_create); 837 838/** 839 * icc_node_destroy() - destroy a node 840 * @id: node id 841 */ 842void icc_node_destroy(int id) 843{ 844 struct icc_node *node; 845 846 mutex_lock(&icc_lock); 847 848 node = node_find(id); 849 if (node) { 850 idr_remove(&icc_idr, node->id); 851 WARN_ON(!hlist_empty(&node->req_list)); 852 } 853 854 mutex_unlock(&icc_lock); 855 856 if (!node) 857 return; 858 859 kfree(node->links); 860 kfree(node); 861} 862EXPORT_SYMBOL_GPL(icc_node_destroy); 863 864/** 865 * icc_link_create() - create a link between two nodes 866 * @node: source node id 867 * @dst_id: destination node id 868 * 869 * Create a link between two nodes. The nodes might belong to different 870 * interconnect providers and the @dst_id node might not exist (if the 871 * provider driver has not probed yet). So just create the @dst_id node 872 * and when the actual provider driver is probed, the rest of the node 873 * data is filled. 874 * 875 * Return: 0 on success, or an error code otherwise 876 */ 877int icc_link_create(struct icc_node *node, const int dst_id) 878{ 879 struct icc_node *dst; 880 struct icc_node **new; 881 int ret = 0; 882 883 if (!node->provider) 884 return -EINVAL; 885 886 mutex_lock(&icc_lock); 887 888 dst = node_find(dst_id); 889 if (!dst) { 890 dst = icc_node_create_nolock(dst_id); 891 892 if (IS_ERR(dst)) { 893 ret = PTR_ERR(dst); 894 goto out; 895 } 896 } 897 898 new = krealloc(node->links, 899 (node->num_links + 1) * sizeof(*node->links), 900 GFP_KERNEL); 901 if (!new) { 902 ret = -ENOMEM; 903 goto out; 904 } 905 906 node->links = new; 907 node->links[node->num_links++] = dst; 908 909out: 910 mutex_unlock(&icc_lock); 911 912 return ret; 913} 914EXPORT_SYMBOL_GPL(icc_link_create); 915 916/** 917 * icc_link_destroy() - destroy a link between two nodes 918 * @src: pointer to source node 919 * @dst: pointer to destination node 920 * 921 * Return: 0 on success, or an error code otherwise 922 */ 923int icc_link_destroy(struct icc_node *src, struct icc_node *dst) 924{ 925 struct icc_node **new; 926 size_t slot; 927 int ret = 0; 928 929 if (IS_ERR_OR_NULL(src)) 930 return -EINVAL; 931 932 if (IS_ERR_OR_NULL(dst)) 933 return -EINVAL; 934 935 mutex_lock(&icc_lock); 936 937 for (slot = 0; slot < src->num_links; slot++) 938 if (src->links[slot] == dst) 939 break; 940 941 if (WARN_ON(slot == src->num_links)) { 942 ret = -ENXIO; 943 goto out; 944 } 945 946 src->links[slot] = src->links[--src->num_links]; 947 948 new = krealloc(src->links, src->num_links * sizeof(*src->links), 949 GFP_KERNEL); 950 if (new) 951 src->links = new; 952 else 953 ret = -ENOMEM; 954 955out: 956 mutex_unlock(&icc_lock); 957 958 return ret; 959} 960EXPORT_SYMBOL_GPL(icc_link_destroy); 961 962/** 963 * icc_node_add() - add interconnect node to interconnect provider 964 * @node: pointer to the interconnect node 965 * @provider: pointer to the interconnect provider 966 */ 967void icc_node_add(struct icc_node *node, struct icc_provider *provider) 968{ 969 mutex_lock(&icc_lock); 970 971 node->provider = provider; 972 list_add_tail(&node->node_list, &provider->nodes); 973 974 /* get the initial bandwidth values and sync them with hardware */ 975 if (provider->get_bw) { 976 provider->get_bw(node, &node->init_avg, &node->init_peak); 977 } else { 978 node->init_avg = INT_MAX; 979 node->init_peak = INT_MAX; 980 } 981 node->avg_bw = node->init_avg; 982 node->peak_bw = node->init_peak; 983 984 if (provider->pre_aggregate) 985 provider->pre_aggregate(node); 986 987 if (provider->aggregate) 988 provider->aggregate(node, 0, node->init_avg, node->init_peak, 989 &node->avg_bw, &node->peak_bw); 990 991 provider->set(node, node); 992 node->avg_bw = 0; 993 node->peak_bw = 0; 994 995 mutex_unlock(&icc_lock); 996} 997EXPORT_SYMBOL_GPL(icc_node_add); 998 999/** 1000 * icc_node_del() - delete interconnect node from interconnect provider 1001 * @node: pointer to the interconnect node 1002 */ 1003void icc_node_del(struct icc_node *node) 1004{ 1005 mutex_lock(&icc_lock); 1006 1007 list_del(&node->node_list); 1008 1009 mutex_unlock(&icc_lock); 1010} 1011EXPORT_SYMBOL_GPL(icc_node_del); 1012 1013/** 1014 * icc_nodes_remove() - remove all previously added nodes from provider 1015 * @provider: the interconnect provider we are removing nodes from 1016 * 1017 * Return: 0 on success, or an error code otherwise 1018 */ 1019int icc_nodes_remove(struct icc_provider *provider) 1020{ 1021 struct icc_node *n, *tmp; 1022 1023 if (WARN_ON(IS_ERR_OR_NULL(provider))) 1024 return -EINVAL; 1025 1026 list_for_each_entry_safe_reverse(n, tmp, &provider->nodes, node_list) { 1027 icc_node_del(n); 1028 icc_node_destroy(n->id); 1029 } 1030 1031 return 0; 1032} 1033EXPORT_SYMBOL_GPL(icc_nodes_remove); 1034 1035/** 1036 * icc_provider_add() - add a new interconnect provider 1037 * @provider: the interconnect provider that will be added into topology 1038 * 1039 * Return: 0 on success, or an error code otherwise 1040 */ 1041int icc_provider_add(struct icc_provider *provider) 1042{ 1043 if (WARN_ON(!provider->set)) 1044 return -EINVAL; 1045 if (WARN_ON(!provider->xlate && !provider->xlate_extended)) 1046 return -EINVAL; 1047 1048 mutex_lock(&icc_lock); 1049 1050 INIT_LIST_HEAD(&provider->nodes); 1051 list_add_tail(&provider->provider_list, &icc_providers); 1052 1053 mutex_unlock(&icc_lock); 1054 1055 dev_dbg(provider->dev, "interconnect provider added to topology\n"); 1056 1057 return 0; 1058} 1059EXPORT_SYMBOL_GPL(icc_provider_add); 1060 1061/** 1062 * icc_provider_del() - delete previously added interconnect provider 1063 * @provider: the interconnect provider that will be removed from topology 1064 * 1065 * Return: 0 on success, or an error code otherwise 1066 */ 1067int icc_provider_del(struct icc_provider *provider) 1068{ 1069 mutex_lock(&icc_lock); 1070 if (provider->users) { 1071 pr_warn("interconnect provider still has %d users\n", 1072 provider->users); 1073 mutex_unlock(&icc_lock); 1074 return -EBUSY; 1075 } 1076 1077 if (!list_empty(&provider->nodes)) { 1078 pr_warn("interconnect provider still has nodes\n"); 1079 mutex_unlock(&icc_lock); 1080 return -EBUSY; 1081 } 1082 1083 list_del(&provider->provider_list); 1084 mutex_unlock(&icc_lock); 1085 1086 return 0; 1087} 1088EXPORT_SYMBOL_GPL(icc_provider_del); 1089 1090static int of_count_icc_providers(struct device_node *np) 1091{ 1092 struct device_node *child; 1093 int count = 0; 1094 const struct of_device_id __maybe_unused ignore_list[] = { 1095 { .compatible = "qcom,sc7180-ipa-virt" }, 1096 {} 1097 }; 1098 1099 for_each_available_child_of_node(np, child) { 1100 if (of_property_read_bool(child, "#interconnect-cells") && 1101 likely(!of_match_node(ignore_list, child))) 1102 count++; 1103 count += of_count_icc_providers(child); 1104 } 1105 1106 return count; 1107} 1108 1109void icc_sync_state(struct device *dev) 1110{ 1111 struct icc_provider *p; 1112 struct icc_node *n; 1113 static int count; 1114 1115 count++; 1116 1117 if (count < providers_count) 1118 return; 1119 1120 mutex_lock(&icc_lock); 1121 synced_state = true; 1122 list_for_each_entry(p, &icc_providers, provider_list) { 1123 dev_dbg(p->dev, "interconnect provider is in synced state\n"); 1124 list_for_each_entry(n, &p->nodes, node_list) { 1125 if (n->init_avg || n->init_peak) { 1126 n->init_avg = 0; 1127 n->init_peak = 0; 1128 aggregate_requests(n); 1129 p->set(n, n); 1130 } 1131 } 1132 } 1133 mutex_unlock(&icc_lock); 1134} 1135EXPORT_SYMBOL_GPL(icc_sync_state); 1136 1137static int __init icc_init(void) 1138{ 1139 struct device_node *root = of_find_node_by_path("/"); 1140 1141 providers_count = of_count_icc_providers(root); 1142 of_node_put(root); 1143 1144 icc_debugfs_dir = debugfs_create_dir("interconnect", NULL); 1145 debugfs_create_file("interconnect_summary", 0444, 1146 icc_debugfs_dir, NULL, &icc_summary_fops); 1147 debugfs_create_file("interconnect_graph", 0444, 1148 icc_debugfs_dir, NULL, &icc_graph_fops); 1149 return 0; 1150} 1151 1152device_initcall(icc_init); 1153 1154MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>"); 1155MODULE_DESCRIPTION("Interconnect Driver Core"); 1156MODULE_LICENSE("GPL v2"); 1157