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