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 int providers_count; 30 static bool synced_state; 31 static DEFINE_MUTEX(icc_lock); 32 static struct dentry *icc_debugfs_dir; 33 34 static 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 43 static 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 } 80 DEFINE_SHOW_ATTRIBUTE(icc_summary); 81 82 static 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 90 static 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 99 static 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 } 144 DEFINE_SHOW_ATTRIBUTE(icc_graph); 145 146 static struct icc_node *node_find(const int id) 147 { 148 return idr_find(&icc_idr, id); 149 } 150 151 static 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 } 176 177 static 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)); 230 231 out: 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 */ 249 250 static 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 } 282 283 static 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 } 307 out: 308 return ret; 309 } 310 311 int 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 } 319 EXPORT_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 */ 331 struct 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 } 344 EXPORT_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 */ 356 struct 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 } 395 EXPORT_SYMBOL_GPL(of_icc_get_from_provider); 396 397 static void devm_icc_release(struct device *dev, void *res) 398 { 399 icc_put(*(struct icc_path **)res); 400 } 401 402 struct 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 } 420 EXPORT_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 */ 437 struct 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 } 510 511 free_icc_data: 512 kfree(src_data); 513 kfree(dst_data); 514 return path; 515 } 516 EXPORT_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 */ 533 struct 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 } 563 EXPORT_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 */ 573 void 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 } 587 EXPORT_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 */ 598 const char *icc_get_name(struct icc_path *path) 599 { 600 if (!path) 601 return NULL; 602 603 return path->name; 604 } 605 EXPORT_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 */ 622 int 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 } 673 EXPORT_SYMBOL_GPL(icc_set_bw); 674 675 static 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 } 695 696 int icc_enable(struct icc_path *path) 697 { 698 return __icc_enable(path, true); 699 } 700 EXPORT_SYMBOL_GPL(icc_enable); 701 702 int icc_disable(struct icc_path *path) 703 { 704 return __icc_enable(path, false); 705 } 706 EXPORT_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 */ 724 struct 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 } 750 out: 751 mutex_unlock(&icc_lock); 752 return path; 753 } 754 EXPORT_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 */ 763 void 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 } 788 EXPORT_SYMBOL_GPL(icc_put); 789 790 static 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 */ 821 struct 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 } 833 EXPORT_SYMBOL_GPL(icc_node_create); 834 835 /** 836 * icc_node_destroy() - destroy a node 837 * @id: node id 838 */ 839 void 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 } 855 EXPORT_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 */ 870 int 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; 901 902 out: 903 mutex_unlock(&icc_lock); 904 905 return ret; 906 } 907 EXPORT_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 */ 916 int 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; 945 946 out: 947 mutex_unlock(&icc_lock); 948 949 return ret; 950 } 951 EXPORT_SYMBOL_GPL(icc_link_destroy); 952 953 /** 954 * icc_node_add() - add interconnect node to interconnect provider 955 * @node: pointer to the interconnect node 956 * @provider: pointer to the interconnect provider 957 */ 958 void icc_node_add(struct icc_node *node, struct icc_provider *provider) 959 { 960 mutex_lock(&icc_lock); 961 962 node->provider = provider; 963 list_add_tail(&node->node_list, &provider->nodes); 964 965 /* get the initial bandwidth values and sync them with hardware */ 966 if (provider->get_bw) { 967 provider->get_bw(node, &node->init_avg, &node->init_peak); 968 } else { 969 node->init_avg = INT_MAX; 970 node->init_peak = INT_MAX; 971 } 972 node->avg_bw = node->init_avg; 973 node->peak_bw = node->init_peak; 974 provider->set(node, node); 975 node->avg_bw = 0; 976 node->peak_bw = 0; 977 978 mutex_unlock(&icc_lock); 979 } 980 EXPORT_SYMBOL_GPL(icc_node_add); 981 982 /** 983 * icc_node_del() - delete interconnect node from interconnect provider 984 * @node: pointer to the interconnect node 985 */ 986 void icc_node_del(struct icc_node *node) 987 { 988 mutex_lock(&icc_lock); 989 990 list_del(&node->node_list); 991 992 mutex_unlock(&icc_lock); 993 } 994 EXPORT_SYMBOL_GPL(icc_node_del); 995 996 /** 997 * icc_nodes_remove() - remove all previously added nodes from provider 998 * @provider: the interconnect provider we are removing nodes from 999 * 1000 * Return: 0 on success, or an error code otherwise 1001 */ 1002 int icc_nodes_remove(struct icc_provider *provider) 1003 { 1004 struct icc_node *n, *tmp; 1005 1006 if (WARN_ON(IS_ERR_OR_NULL(provider))) 1007 return -EINVAL; 1008 1009 list_for_each_entry_safe_reverse(n, tmp, &provider->nodes, node_list) { 1010 icc_node_del(n); 1011 icc_node_destroy(n->id); 1012 } 1013 1014 return 0; 1015 } 1016 EXPORT_SYMBOL_GPL(icc_nodes_remove); 1017 1018 /** 1019 * icc_provider_add() - add a new interconnect provider 1020 * @provider: the interconnect provider that will be added into topology 1021 * 1022 * Return: 0 on success, or an error code otherwise 1023 */ 1024 int icc_provider_add(struct icc_provider *provider) 1025 { 1026 if (WARN_ON(!provider->set)) 1027 return -EINVAL; 1028 if (WARN_ON(!provider->xlate && !provider->xlate_extended)) 1029 return -EINVAL; 1030 1031 mutex_lock(&icc_lock); 1032 1033 INIT_LIST_HEAD(&provider->nodes); 1034 list_add_tail(&provider->provider_list, &icc_providers); 1035 1036 mutex_unlock(&icc_lock); 1037 1038 dev_dbg(provider->dev, "interconnect provider added to topology\n"); 1039 1040 return 0; 1041 } 1042 EXPORT_SYMBOL_GPL(icc_provider_add); 1043 1044 /** 1045 * icc_provider_del() - delete previously added interconnect provider 1046 * @provider: the interconnect provider that will be removed from topology 1047 * 1048 * Return: 0 on success, or an error code otherwise 1049 */ 1050 int icc_provider_del(struct icc_provider *provider) 1051 { 1052 mutex_lock(&icc_lock); 1053 if (provider->users) { 1054 pr_warn("interconnect provider still has %d users\n", 1055 provider->users); 1056 mutex_unlock(&icc_lock); 1057 return -EBUSY; 1058 } 1059 1060 if (!list_empty(&provider->nodes)) { 1061 pr_warn("interconnect provider still has nodes\n"); 1062 mutex_unlock(&icc_lock); 1063 return -EBUSY; 1064 } 1065 1066 list_del(&provider->provider_list); 1067 mutex_unlock(&icc_lock); 1068 1069 return 0; 1070 } 1071 EXPORT_SYMBOL_GPL(icc_provider_del); 1072 1073 static int of_count_icc_providers(struct device_node *np) 1074 { 1075 struct device_node *child; 1076 int count = 0; 1077 1078 for_each_available_child_of_node(np, child) { 1079 if (of_property_read_bool(child, "#interconnect-cells")) 1080 count++; 1081 count += of_count_icc_providers(child); 1082 } 1083 of_node_put(np); 1084 1085 return count; 1086 } 1087 1088 void icc_sync_state(struct device *dev) 1089 { 1090 struct icc_provider *p; 1091 struct icc_node *n; 1092 static int count; 1093 1094 count++; 1095 1096 if (count < providers_count) 1097 return; 1098 1099 mutex_lock(&icc_lock); 1100 synced_state = true; 1101 list_for_each_entry(p, &icc_providers, provider_list) { 1102 dev_dbg(p->dev, "interconnect provider is in synced state\n"); 1103 list_for_each_entry(n, &p->nodes, node_list) { 1104 if (n->init_avg || n->init_peak) { 1105 aggregate_requests(n); 1106 p->set(n, n); 1107 } 1108 } 1109 } 1110 mutex_unlock(&icc_lock); 1111 } 1112 EXPORT_SYMBOL_GPL(icc_sync_state); 1113 1114 static int __init icc_init(void) 1115 { 1116 struct device_node *root = of_find_node_by_path("/"); 1117 1118 providers_count = of_count_icc_providers(root); 1119 of_node_put(root); 1120 1121 icc_debugfs_dir = debugfs_create_dir("interconnect", NULL); 1122 debugfs_create_file("interconnect_summary", 0444, 1123 icc_debugfs_dir, NULL, &icc_summary_fops); 1124 debugfs_create_file("interconnect_graph", 0444, 1125 icc_debugfs_dir, NULL, &icc_graph_fops); 1126 return 0; 1127 } 1128 1129 device_initcall(icc_init); 1130 1131 MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>"); 1132 MODULE_DESCRIPTION("Interconnect Driver Core"); 1133 MODULE_LICENSE("GPL v2"); 1134