1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * cacheinfo support - processor cache information via sysfs 4 * 5 * Based on arch/x86/kernel/cpu/intel_cacheinfo.c 6 * Author: Sudeep Holla <sudeep.holla@arm.com> 7 */ 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/acpi.h> 11 #include <linux/bitops.h> 12 #include <linux/cacheinfo.h> 13 #include <linux/compiler.h> 14 #include <linux/cpu.h> 15 #include <linux/device.h> 16 #include <linux/init.h> 17 #include <linux/of.h> 18 #include <linux/sched.h> 19 #include <linux/slab.h> 20 #include <linux/smp.h> 21 #include <linux/sysfs.h> 22 23 /* pointer to per cpu cacheinfo */ 24 static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo); 25 #define ci_cacheinfo(cpu) (&per_cpu(ci_cpu_cacheinfo, cpu)) 26 #define cache_leaves(cpu) (ci_cacheinfo(cpu)->num_leaves) 27 #define per_cpu_cacheinfo(cpu) (ci_cacheinfo(cpu)->info_list) 28 29 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu) 30 { 31 return ci_cacheinfo(cpu); 32 } 33 34 #ifdef CONFIG_OF 35 static int cache_setup_of_node(unsigned int cpu) 36 { 37 struct device_node *np; 38 struct cacheinfo *this_leaf; 39 struct device *cpu_dev = get_cpu_device(cpu); 40 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 41 unsigned int index = 0; 42 43 /* skip if of_node is already populated */ 44 if (this_cpu_ci->info_list->of_node) 45 return 0; 46 47 if (!cpu_dev) { 48 pr_err("No cpu device for CPU %d\n", cpu); 49 return -ENODEV; 50 } 51 np = cpu_dev->of_node; 52 if (!np) { 53 pr_err("Failed to find cpu%d device node\n", cpu); 54 return -ENOENT; 55 } 56 57 while (index < cache_leaves(cpu)) { 58 this_leaf = this_cpu_ci->info_list + index; 59 if (this_leaf->level != 1) 60 np = of_find_next_cache_node(np); 61 else 62 np = of_node_get(np);/* cpu node itself */ 63 if (!np) 64 break; 65 this_leaf->of_node = np; 66 index++; 67 } 68 69 if (index != cache_leaves(cpu)) /* not all OF nodes populated */ 70 return -ENOENT; 71 72 return 0; 73 } 74 75 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, 76 struct cacheinfo *sib_leaf) 77 { 78 return sib_leaf->of_node == this_leaf->of_node; 79 } 80 81 /* OF properties to query for a given cache type */ 82 struct cache_type_info { 83 const char *size_prop; 84 const char *line_size_props[2]; 85 const char *nr_sets_prop; 86 }; 87 88 static const struct cache_type_info cache_type_info[] = { 89 { 90 .size_prop = "cache-size", 91 .line_size_props = { "cache-line-size", 92 "cache-block-size", }, 93 .nr_sets_prop = "cache-sets", 94 }, { 95 .size_prop = "i-cache-size", 96 .line_size_props = { "i-cache-line-size", 97 "i-cache-block-size", }, 98 .nr_sets_prop = "i-cache-sets", 99 }, { 100 .size_prop = "d-cache-size", 101 .line_size_props = { "d-cache-line-size", 102 "d-cache-block-size", }, 103 .nr_sets_prop = "d-cache-sets", 104 }, 105 }; 106 107 static inline int get_cacheinfo_idx(enum cache_type type) 108 { 109 if (type == CACHE_TYPE_UNIFIED) 110 return 0; 111 return type; 112 } 113 114 static void cache_size(struct cacheinfo *this_leaf) 115 { 116 const char *propname; 117 const __be32 *cache_size; 118 int ct_idx; 119 120 ct_idx = get_cacheinfo_idx(this_leaf->type); 121 propname = cache_type_info[ct_idx].size_prop; 122 123 cache_size = of_get_property(this_leaf->of_node, propname, NULL); 124 if (cache_size) 125 this_leaf->size = of_read_number(cache_size, 1); 126 } 127 128 /* not cache_line_size() because that's a macro in include/linux/cache.h */ 129 static void cache_get_line_size(struct cacheinfo *this_leaf) 130 { 131 const __be32 *line_size; 132 int i, lim, ct_idx; 133 134 ct_idx = get_cacheinfo_idx(this_leaf->type); 135 lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props); 136 137 for (i = 0; i < lim; i++) { 138 const char *propname; 139 140 propname = cache_type_info[ct_idx].line_size_props[i]; 141 line_size = of_get_property(this_leaf->of_node, propname, NULL); 142 if (line_size) 143 break; 144 } 145 146 if (line_size) 147 this_leaf->coherency_line_size = of_read_number(line_size, 1); 148 } 149 150 static void cache_nr_sets(struct cacheinfo *this_leaf) 151 { 152 const char *propname; 153 const __be32 *nr_sets; 154 int ct_idx; 155 156 ct_idx = get_cacheinfo_idx(this_leaf->type); 157 propname = cache_type_info[ct_idx].nr_sets_prop; 158 159 nr_sets = of_get_property(this_leaf->of_node, propname, NULL); 160 if (nr_sets) 161 this_leaf->number_of_sets = of_read_number(nr_sets, 1); 162 } 163 164 static void cache_associativity(struct cacheinfo *this_leaf) 165 { 166 unsigned int line_size = this_leaf->coherency_line_size; 167 unsigned int nr_sets = this_leaf->number_of_sets; 168 unsigned int size = this_leaf->size; 169 170 /* 171 * If the cache is fully associative, there is no need to 172 * check the other properties. 173 */ 174 if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0)) 175 this_leaf->ways_of_associativity = (size / nr_sets) / line_size; 176 } 177 178 static bool cache_node_is_unified(struct cacheinfo *this_leaf) 179 { 180 return of_property_read_bool(this_leaf->of_node, "cache-unified"); 181 } 182 183 static void cache_of_override_properties(unsigned int cpu) 184 { 185 int index; 186 struct cacheinfo *this_leaf; 187 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 188 189 for (index = 0; index < cache_leaves(cpu); index++) { 190 this_leaf = this_cpu_ci->info_list + index; 191 /* 192 * init_cache_level must setup the cache level correctly 193 * overriding the architecturally specified levels, so 194 * if type is NONE at this stage, it should be unified 195 */ 196 if (this_leaf->type == CACHE_TYPE_NOCACHE && 197 cache_node_is_unified(this_leaf)) 198 this_leaf->type = CACHE_TYPE_UNIFIED; 199 cache_size(this_leaf); 200 cache_get_line_size(this_leaf); 201 cache_nr_sets(this_leaf); 202 cache_associativity(this_leaf); 203 } 204 } 205 #else 206 static void cache_of_override_properties(unsigned int cpu) { } 207 static inline int cache_setup_of_node(unsigned int cpu) { return 0; } 208 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, 209 struct cacheinfo *sib_leaf) 210 { 211 /* 212 * For non-DT systems, assume unique level 1 cache, system-wide 213 * shared caches for all other levels. This will be used only if 214 * arch specific code has not populated shared_cpu_map 215 */ 216 return !(this_leaf->level == 1); 217 } 218 #endif 219 220 static int cache_shared_cpu_map_setup(unsigned int cpu) 221 { 222 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 223 struct cacheinfo *this_leaf, *sib_leaf; 224 unsigned int index; 225 int ret = 0; 226 227 if (this_cpu_ci->cpu_map_populated) 228 return 0; 229 230 if (of_have_populated_dt()) 231 ret = cache_setup_of_node(cpu); 232 else if (!acpi_disabled) 233 /* No cache property/hierarchy support yet in ACPI */ 234 ret = -ENOTSUPP; 235 if (ret) 236 return ret; 237 238 for (index = 0; index < cache_leaves(cpu); index++) { 239 unsigned int i; 240 241 this_leaf = this_cpu_ci->info_list + index; 242 /* skip if shared_cpu_map is already populated */ 243 if (!cpumask_empty(&this_leaf->shared_cpu_map)) 244 continue; 245 246 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map); 247 for_each_online_cpu(i) { 248 struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i); 249 250 if (i == cpu || !sib_cpu_ci->info_list) 251 continue;/* skip if itself or no cacheinfo */ 252 sib_leaf = sib_cpu_ci->info_list + index; 253 if (cache_leaves_are_shared(this_leaf, sib_leaf)) { 254 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map); 255 cpumask_set_cpu(i, &this_leaf->shared_cpu_map); 256 } 257 } 258 } 259 260 return 0; 261 } 262 263 static void cache_shared_cpu_map_remove(unsigned int cpu) 264 { 265 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 266 struct cacheinfo *this_leaf, *sib_leaf; 267 unsigned int sibling, index; 268 269 for (index = 0; index < cache_leaves(cpu); index++) { 270 this_leaf = this_cpu_ci->info_list + index; 271 for_each_cpu(sibling, &this_leaf->shared_cpu_map) { 272 struct cpu_cacheinfo *sib_cpu_ci; 273 274 if (sibling == cpu) /* skip itself */ 275 continue; 276 277 sib_cpu_ci = get_cpu_cacheinfo(sibling); 278 if (!sib_cpu_ci->info_list) 279 continue; 280 281 sib_leaf = sib_cpu_ci->info_list + index; 282 cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); 283 cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); 284 } 285 of_node_put(this_leaf->of_node); 286 } 287 } 288 289 static void cache_override_properties(unsigned int cpu) 290 { 291 if (of_have_populated_dt()) 292 return cache_of_override_properties(cpu); 293 } 294 295 static void free_cache_attributes(unsigned int cpu) 296 { 297 if (!per_cpu_cacheinfo(cpu)) 298 return; 299 300 cache_shared_cpu_map_remove(cpu); 301 302 kfree(per_cpu_cacheinfo(cpu)); 303 per_cpu_cacheinfo(cpu) = NULL; 304 } 305 306 int __weak init_cache_level(unsigned int cpu) 307 { 308 return -ENOENT; 309 } 310 311 int __weak populate_cache_leaves(unsigned int cpu) 312 { 313 return -ENOENT; 314 } 315 316 static int detect_cache_attributes(unsigned int cpu) 317 { 318 int ret; 319 320 if (init_cache_level(cpu) || !cache_leaves(cpu)) 321 return -ENOENT; 322 323 per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu), 324 sizeof(struct cacheinfo), GFP_KERNEL); 325 if (per_cpu_cacheinfo(cpu) == NULL) 326 return -ENOMEM; 327 328 ret = populate_cache_leaves(cpu); 329 if (ret) 330 goto free_ci; 331 /* 332 * For systems using DT for cache hierarchy, of_node and shared_cpu_map 333 * will be set up here only if they are not populated already 334 */ 335 ret = cache_shared_cpu_map_setup(cpu); 336 if (ret) { 337 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu); 338 goto free_ci; 339 } 340 341 cache_override_properties(cpu); 342 return 0; 343 344 free_ci: 345 free_cache_attributes(cpu); 346 return ret; 347 } 348 349 /* pointer to cpuX/cache device */ 350 static DEFINE_PER_CPU(struct device *, ci_cache_dev); 351 #define per_cpu_cache_dev(cpu) (per_cpu(ci_cache_dev, cpu)) 352 353 static cpumask_t cache_dev_map; 354 355 /* pointer to array of devices for cpuX/cache/indexY */ 356 static DEFINE_PER_CPU(struct device **, ci_index_dev); 357 #define per_cpu_index_dev(cpu) (per_cpu(ci_index_dev, cpu)) 358 #define per_cache_index_dev(cpu, idx) ((per_cpu_index_dev(cpu))[idx]) 359 360 #define show_one(file_name, object) \ 361 static ssize_t file_name##_show(struct device *dev, \ 362 struct device_attribute *attr, char *buf) \ 363 { \ 364 struct cacheinfo *this_leaf = dev_get_drvdata(dev); \ 365 return sprintf(buf, "%u\n", this_leaf->object); \ 366 } 367 368 show_one(id, id); 369 show_one(level, level); 370 show_one(coherency_line_size, coherency_line_size); 371 show_one(number_of_sets, number_of_sets); 372 show_one(physical_line_partition, physical_line_partition); 373 show_one(ways_of_associativity, ways_of_associativity); 374 375 static ssize_t size_show(struct device *dev, 376 struct device_attribute *attr, char *buf) 377 { 378 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 379 380 return sprintf(buf, "%uK\n", this_leaf->size >> 10); 381 } 382 383 static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf) 384 { 385 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 386 const struct cpumask *mask = &this_leaf->shared_cpu_map; 387 388 return cpumap_print_to_pagebuf(list, buf, mask); 389 } 390 391 static ssize_t shared_cpu_map_show(struct device *dev, 392 struct device_attribute *attr, char *buf) 393 { 394 return shared_cpumap_show_func(dev, false, buf); 395 } 396 397 static ssize_t shared_cpu_list_show(struct device *dev, 398 struct device_attribute *attr, char *buf) 399 { 400 return shared_cpumap_show_func(dev, true, buf); 401 } 402 403 static ssize_t type_show(struct device *dev, 404 struct device_attribute *attr, char *buf) 405 { 406 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 407 408 switch (this_leaf->type) { 409 case CACHE_TYPE_DATA: 410 return sprintf(buf, "Data\n"); 411 case CACHE_TYPE_INST: 412 return sprintf(buf, "Instruction\n"); 413 case CACHE_TYPE_UNIFIED: 414 return sprintf(buf, "Unified\n"); 415 default: 416 return -EINVAL; 417 } 418 } 419 420 static ssize_t allocation_policy_show(struct device *dev, 421 struct device_attribute *attr, char *buf) 422 { 423 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 424 unsigned int ci_attr = this_leaf->attributes; 425 int n = 0; 426 427 if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE)) 428 n = sprintf(buf, "ReadWriteAllocate\n"); 429 else if (ci_attr & CACHE_READ_ALLOCATE) 430 n = sprintf(buf, "ReadAllocate\n"); 431 else if (ci_attr & CACHE_WRITE_ALLOCATE) 432 n = sprintf(buf, "WriteAllocate\n"); 433 return n; 434 } 435 436 static ssize_t write_policy_show(struct device *dev, 437 struct device_attribute *attr, char *buf) 438 { 439 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 440 unsigned int ci_attr = this_leaf->attributes; 441 int n = 0; 442 443 if (ci_attr & CACHE_WRITE_THROUGH) 444 n = sprintf(buf, "WriteThrough\n"); 445 else if (ci_attr & CACHE_WRITE_BACK) 446 n = sprintf(buf, "WriteBack\n"); 447 return n; 448 } 449 450 static DEVICE_ATTR_RO(id); 451 static DEVICE_ATTR_RO(level); 452 static DEVICE_ATTR_RO(type); 453 static DEVICE_ATTR_RO(coherency_line_size); 454 static DEVICE_ATTR_RO(ways_of_associativity); 455 static DEVICE_ATTR_RO(number_of_sets); 456 static DEVICE_ATTR_RO(size); 457 static DEVICE_ATTR_RO(allocation_policy); 458 static DEVICE_ATTR_RO(write_policy); 459 static DEVICE_ATTR_RO(shared_cpu_map); 460 static DEVICE_ATTR_RO(shared_cpu_list); 461 static DEVICE_ATTR_RO(physical_line_partition); 462 463 static struct attribute *cache_default_attrs[] = { 464 &dev_attr_id.attr, 465 &dev_attr_type.attr, 466 &dev_attr_level.attr, 467 &dev_attr_shared_cpu_map.attr, 468 &dev_attr_shared_cpu_list.attr, 469 &dev_attr_coherency_line_size.attr, 470 &dev_attr_ways_of_associativity.attr, 471 &dev_attr_number_of_sets.attr, 472 &dev_attr_size.attr, 473 &dev_attr_allocation_policy.attr, 474 &dev_attr_write_policy.attr, 475 &dev_attr_physical_line_partition.attr, 476 NULL 477 }; 478 479 static umode_t 480 cache_default_attrs_is_visible(struct kobject *kobj, 481 struct attribute *attr, int unused) 482 { 483 struct device *dev = kobj_to_dev(kobj); 484 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 485 const struct cpumask *mask = &this_leaf->shared_cpu_map; 486 umode_t mode = attr->mode; 487 488 if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID)) 489 return mode; 490 if ((attr == &dev_attr_type.attr) && this_leaf->type) 491 return mode; 492 if ((attr == &dev_attr_level.attr) && this_leaf->level) 493 return mode; 494 if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask)) 495 return mode; 496 if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask)) 497 return mode; 498 if ((attr == &dev_attr_coherency_line_size.attr) && 499 this_leaf->coherency_line_size) 500 return mode; 501 if ((attr == &dev_attr_ways_of_associativity.attr) && 502 this_leaf->size) /* allow 0 = full associativity */ 503 return mode; 504 if ((attr == &dev_attr_number_of_sets.attr) && 505 this_leaf->number_of_sets) 506 return mode; 507 if ((attr == &dev_attr_size.attr) && this_leaf->size) 508 return mode; 509 if ((attr == &dev_attr_write_policy.attr) && 510 (this_leaf->attributes & CACHE_WRITE_POLICY_MASK)) 511 return mode; 512 if ((attr == &dev_attr_allocation_policy.attr) && 513 (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK)) 514 return mode; 515 if ((attr == &dev_attr_physical_line_partition.attr) && 516 this_leaf->physical_line_partition) 517 return mode; 518 519 return 0; 520 } 521 522 static const struct attribute_group cache_default_group = { 523 .attrs = cache_default_attrs, 524 .is_visible = cache_default_attrs_is_visible, 525 }; 526 527 static const struct attribute_group *cache_default_groups[] = { 528 &cache_default_group, 529 NULL, 530 }; 531 532 static const struct attribute_group *cache_private_groups[] = { 533 &cache_default_group, 534 NULL, /* Place holder for private group */ 535 NULL, 536 }; 537 538 const struct attribute_group * 539 __weak cache_get_priv_group(struct cacheinfo *this_leaf) 540 { 541 return NULL; 542 } 543 544 static const struct attribute_group ** 545 cache_get_attribute_groups(struct cacheinfo *this_leaf) 546 { 547 const struct attribute_group *priv_group = 548 cache_get_priv_group(this_leaf); 549 550 if (!priv_group) 551 return cache_default_groups; 552 553 if (!cache_private_groups[1]) 554 cache_private_groups[1] = priv_group; 555 556 return cache_private_groups; 557 } 558 559 /* Add/Remove cache interface for CPU device */ 560 static void cpu_cache_sysfs_exit(unsigned int cpu) 561 { 562 int i; 563 struct device *ci_dev; 564 565 if (per_cpu_index_dev(cpu)) { 566 for (i = 0; i < cache_leaves(cpu); i++) { 567 ci_dev = per_cache_index_dev(cpu, i); 568 if (!ci_dev) 569 continue; 570 device_unregister(ci_dev); 571 } 572 kfree(per_cpu_index_dev(cpu)); 573 per_cpu_index_dev(cpu) = NULL; 574 } 575 device_unregister(per_cpu_cache_dev(cpu)); 576 per_cpu_cache_dev(cpu) = NULL; 577 } 578 579 static int cpu_cache_sysfs_init(unsigned int cpu) 580 { 581 struct device *dev = get_cpu_device(cpu); 582 583 if (per_cpu_cacheinfo(cpu) == NULL) 584 return -ENOENT; 585 586 per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache"); 587 if (IS_ERR(per_cpu_cache_dev(cpu))) 588 return PTR_ERR(per_cpu_cache_dev(cpu)); 589 590 /* Allocate all required memory */ 591 per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu), 592 sizeof(struct device *), GFP_KERNEL); 593 if (unlikely(per_cpu_index_dev(cpu) == NULL)) 594 goto err_out; 595 596 return 0; 597 598 err_out: 599 cpu_cache_sysfs_exit(cpu); 600 return -ENOMEM; 601 } 602 603 static int cache_add_dev(unsigned int cpu) 604 { 605 unsigned int i; 606 int rc; 607 struct device *ci_dev, *parent; 608 struct cacheinfo *this_leaf; 609 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 610 const struct attribute_group **cache_groups; 611 612 rc = cpu_cache_sysfs_init(cpu); 613 if (unlikely(rc < 0)) 614 return rc; 615 616 parent = per_cpu_cache_dev(cpu); 617 for (i = 0; i < cache_leaves(cpu); i++) { 618 this_leaf = this_cpu_ci->info_list + i; 619 if (this_leaf->disable_sysfs) 620 continue; 621 cache_groups = cache_get_attribute_groups(this_leaf); 622 ci_dev = cpu_device_create(parent, this_leaf, cache_groups, 623 "index%1u", i); 624 if (IS_ERR(ci_dev)) { 625 rc = PTR_ERR(ci_dev); 626 goto err; 627 } 628 per_cache_index_dev(cpu, i) = ci_dev; 629 } 630 cpumask_set_cpu(cpu, &cache_dev_map); 631 632 return 0; 633 err: 634 cpu_cache_sysfs_exit(cpu); 635 return rc; 636 } 637 638 static int cacheinfo_cpu_online(unsigned int cpu) 639 { 640 int rc = detect_cache_attributes(cpu); 641 642 if (rc) 643 return rc; 644 rc = cache_add_dev(cpu); 645 if (rc) 646 free_cache_attributes(cpu); 647 return rc; 648 } 649 650 static int cacheinfo_cpu_pre_down(unsigned int cpu) 651 { 652 if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map)) 653 cpu_cache_sysfs_exit(cpu); 654 655 free_cache_attributes(cpu); 656 return 0; 657 } 658 659 static int __init cacheinfo_sysfs_init(void) 660 { 661 return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online", 662 cacheinfo_cpu_online, cacheinfo_cpu_pre_down); 663 } 664 device_initcall(cacheinfo_sysfs_init); 665