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 inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, 36 struct cacheinfo *sib_leaf) 37 { 38 return sib_leaf->fw_token == this_leaf->fw_token; 39 } 40 41 /* OF properties to query for a given cache type */ 42 struct cache_type_info { 43 const char *size_prop; 44 const char *line_size_props[2]; 45 const char *nr_sets_prop; 46 }; 47 48 static const struct cache_type_info cache_type_info[] = { 49 { 50 .size_prop = "cache-size", 51 .line_size_props = { "cache-line-size", 52 "cache-block-size", }, 53 .nr_sets_prop = "cache-sets", 54 }, { 55 .size_prop = "i-cache-size", 56 .line_size_props = { "i-cache-line-size", 57 "i-cache-block-size", }, 58 .nr_sets_prop = "i-cache-sets", 59 }, { 60 .size_prop = "d-cache-size", 61 .line_size_props = { "d-cache-line-size", 62 "d-cache-block-size", }, 63 .nr_sets_prop = "d-cache-sets", 64 }, 65 }; 66 67 static inline int get_cacheinfo_idx(enum cache_type type) 68 { 69 if (type == CACHE_TYPE_UNIFIED) 70 return 0; 71 return type; 72 } 73 74 static void cache_size(struct cacheinfo *this_leaf, struct device_node *np) 75 { 76 const char *propname; 77 const __be32 *cache_size; 78 int ct_idx; 79 80 ct_idx = get_cacheinfo_idx(this_leaf->type); 81 propname = cache_type_info[ct_idx].size_prop; 82 83 cache_size = of_get_property(np, propname, NULL); 84 if (cache_size) 85 this_leaf->size = of_read_number(cache_size, 1); 86 } 87 88 /* not cache_line_size() because that's a macro in include/linux/cache.h */ 89 static void cache_get_line_size(struct cacheinfo *this_leaf, 90 struct device_node *np) 91 { 92 const __be32 *line_size; 93 int i, lim, ct_idx; 94 95 ct_idx = get_cacheinfo_idx(this_leaf->type); 96 lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props); 97 98 for (i = 0; i < lim; i++) { 99 const char *propname; 100 101 propname = cache_type_info[ct_idx].line_size_props[i]; 102 line_size = of_get_property(np, propname, NULL); 103 if (line_size) 104 break; 105 } 106 107 if (line_size) 108 this_leaf->coherency_line_size = of_read_number(line_size, 1); 109 } 110 111 static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np) 112 { 113 const char *propname; 114 const __be32 *nr_sets; 115 int ct_idx; 116 117 ct_idx = get_cacheinfo_idx(this_leaf->type); 118 propname = cache_type_info[ct_idx].nr_sets_prop; 119 120 nr_sets = of_get_property(np, propname, NULL); 121 if (nr_sets) 122 this_leaf->number_of_sets = of_read_number(nr_sets, 1); 123 } 124 125 static void cache_associativity(struct cacheinfo *this_leaf) 126 { 127 unsigned int line_size = this_leaf->coherency_line_size; 128 unsigned int nr_sets = this_leaf->number_of_sets; 129 unsigned int size = this_leaf->size; 130 131 /* 132 * If the cache is fully associative, there is no need to 133 * check the other properties. 134 */ 135 if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0)) 136 this_leaf->ways_of_associativity = (size / nr_sets) / line_size; 137 } 138 139 static bool cache_node_is_unified(struct cacheinfo *this_leaf, 140 struct device_node *np) 141 { 142 return of_property_read_bool(np, "cache-unified"); 143 } 144 145 static void cache_of_set_props(struct cacheinfo *this_leaf, 146 struct device_node *np) 147 { 148 /* 149 * init_cache_level must setup the cache level correctly 150 * overriding the architecturally specified levels, so 151 * if type is NONE at this stage, it should be unified 152 */ 153 if (this_leaf->type == CACHE_TYPE_NOCACHE && 154 cache_node_is_unified(this_leaf, np)) 155 this_leaf->type = CACHE_TYPE_UNIFIED; 156 cache_size(this_leaf, np); 157 cache_get_line_size(this_leaf, np); 158 cache_nr_sets(this_leaf, np); 159 cache_associativity(this_leaf); 160 } 161 162 static int cache_setup_of_node(unsigned int cpu) 163 { 164 struct device_node *np; 165 struct cacheinfo *this_leaf; 166 struct device *cpu_dev = get_cpu_device(cpu); 167 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 168 unsigned int index = 0; 169 170 /* skip if fw_token is already populated */ 171 if (this_cpu_ci->info_list->fw_token) { 172 return 0; 173 } 174 175 if (!cpu_dev) { 176 pr_err("No cpu device for CPU %d\n", cpu); 177 return -ENODEV; 178 } 179 np = cpu_dev->of_node; 180 if (!np) { 181 pr_err("Failed to find cpu%d device node\n", cpu); 182 return -ENOENT; 183 } 184 185 while (index < cache_leaves(cpu)) { 186 this_leaf = this_cpu_ci->info_list + index; 187 if (this_leaf->level != 1) 188 np = of_find_next_cache_node(np); 189 else 190 np = of_node_get(np);/* cpu node itself */ 191 if (!np) 192 break; 193 cache_of_set_props(this_leaf, np); 194 this_leaf->fw_token = np; 195 index++; 196 } 197 198 if (index != cache_leaves(cpu)) /* not all OF nodes populated */ 199 return -ENOENT; 200 201 return 0; 202 } 203 #else 204 static inline int cache_setup_of_node(unsigned int cpu) { return 0; } 205 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, 206 struct cacheinfo *sib_leaf) 207 { 208 /* 209 * For non-DT/ACPI systems, assume unique level 1 caches, system-wide 210 * shared caches for all other levels. This will be used only if 211 * arch specific code has not populated shared_cpu_map 212 */ 213 return !(this_leaf->level == 1); 214 } 215 #endif 216 217 int __weak cache_setup_acpi(unsigned int cpu) 218 { 219 return -ENOTSUPP; 220 } 221 222 static int cache_shared_cpu_map_setup(unsigned int cpu) 223 { 224 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 225 struct cacheinfo *this_leaf, *sib_leaf; 226 unsigned int index; 227 int ret = 0; 228 229 if (this_cpu_ci->cpu_map_populated) 230 return 0; 231 232 if (of_have_populated_dt()) 233 ret = cache_setup_of_node(cpu); 234 else if (!acpi_disabled) 235 ret = cache_setup_acpi(cpu); 236 237 if (ret) 238 return ret; 239 240 for (index = 0; index < cache_leaves(cpu); index++) { 241 unsigned int i; 242 243 this_leaf = this_cpu_ci->info_list + index; 244 /* skip if shared_cpu_map is already populated */ 245 if (!cpumask_empty(&this_leaf->shared_cpu_map)) 246 continue; 247 248 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map); 249 for_each_online_cpu(i) { 250 struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i); 251 252 if (i == cpu || !sib_cpu_ci->info_list) 253 continue;/* skip if itself or no cacheinfo */ 254 sib_leaf = sib_cpu_ci->info_list + index; 255 if (cache_leaves_are_shared(this_leaf, sib_leaf)) { 256 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map); 257 cpumask_set_cpu(i, &this_leaf->shared_cpu_map); 258 } 259 } 260 } 261 262 return 0; 263 } 264 265 static void cache_shared_cpu_map_remove(unsigned int cpu) 266 { 267 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 268 struct cacheinfo *this_leaf, *sib_leaf; 269 unsigned int sibling, index; 270 271 for (index = 0; index < cache_leaves(cpu); index++) { 272 this_leaf = this_cpu_ci->info_list + index; 273 for_each_cpu(sibling, &this_leaf->shared_cpu_map) { 274 struct cpu_cacheinfo *sib_cpu_ci; 275 276 if (sibling == cpu) /* skip itself */ 277 continue; 278 279 sib_cpu_ci = get_cpu_cacheinfo(sibling); 280 if (!sib_cpu_ci->info_list) 281 continue; 282 283 sib_leaf = sib_cpu_ci->info_list + index; 284 cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); 285 cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); 286 } 287 if (of_have_populated_dt()) 288 of_node_put(this_leaf->fw_token); 289 } 290 } 291 292 static void free_cache_attributes(unsigned int cpu) 293 { 294 if (!per_cpu_cacheinfo(cpu)) 295 return; 296 297 cache_shared_cpu_map_remove(cpu); 298 299 kfree(per_cpu_cacheinfo(cpu)); 300 per_cpu_cacheinfo(cpu) = NULL; 301 } 302 303 int __weak init_cache_level(unsigned int cpu) 304 { 305 return -ENOENT; 306 } 307 308 int __weak populate_cache_leaves(unsigned int cpu) 309 { 310 return -ENOENT; 311 } 312 313 static int detect_cache_attributes(unsigned int cpu) 314 { 315 int ret; 316 317 if (init_cache_level(cpu) || !cache_leaves(cpu)) 318 return -ENOENT; 319 320 per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu), 321 sizeof(struct cacheinfo), GFP_KERNEL); 322 if (per_cpu_cacheinfo(cpu) == NULL) 323 return -ENOMEM; 324 325 /* 326 * populate_cache_leaves() may completely setup the cache leaves and 327 * shared_cpu_map or it may leave it partially setup. 328 */ 329 ret = populate_cache_leaves(cpu); 330 if (ret) 331 goto free_ci; 332 /* 333 * For systems using DT for cache hierarchy, fw_token 334 * and shared_cpu_map will be set up here only if they are 335 * not populated already 336 */ 337 ret = cache_shared_cpu_map_setup(cpu); 338 if (ret) { 339 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu); 340 goto free_ci; 341 } 342 343 return 0; 344 345 free_ci: 346 free_cache_attributes(cpu); 347 return ret; 348 } 349 350 /* pointer to cpuX/cache device */ 351 static DEFINE_PER_CPU(struct device *, ci_cache_dev); 352 #define per_cpu_cache_dev(cpu) (per_cpu(ci_cache_dev, cpu)) 353 354 static cpumask_t cache_dev_map; 355 356 /* pointer to array of devices for cpuX/cache/indexY */ 357 static DEFINE_PER_CPU(struct device **, ci_index_dev); 358 #define per_cpu_index_dev(cpu) (per_cpu(ci_index_dev, cpu)) 359 #define per_cache_index_dev(cpu, idx) ((per_cpu_index_dev(cpu))[idx]) 360 361 #define show_one(file_name, object) \ 362 static ssize_t file_name##_show(struct device *dev, \ 363 struct device_attribute *attr, char *buf) \ 364 { \ 365 struct cacheinfo *this_leaf = dev_get_drvdata(dev); \ 366 return sprintf(buf, "%u\n", this_leaf->object); \ 367 } 368 369 show_one(id, id); 370 show_one(level, level); 371 show_one(coherency_line_size, coherency_line_size); 372 show_one(number_of_sets, number_of_sets); 373 show_one(physical_line_partition, physical_line_partition); 374 show_one(ways_of_associativity, ways_of_associativity); 375 376 static ssize_t size_show(struct device *dev, 377 struct device_attribute *attr, char *buf) 378 { 379 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 380 381 return sprintf(buf, "%uK\n", this_leaf->size >> 10); 382 } 383 384 static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf) 385 { 386 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 387 const struct cpumask *mask = &this_leaf->shared_cpu_map; 388 389 return cpumap_print_to_pagebuf(list, buf, mask); 390 } 391 392 static ssize_t shared_cpu_map_show(struct device *dev, 393 struct device_attribute *attr, char *buf) 394 { 395 return shared_cpumap_show_func(dev, false, buf); 396 } 397 398 static ssize_t shared_cpu_list_show(struct device *dev, 399 struct device_attribute *attr, char *buf) 400 { 401 return shared_cpumap_show_func(dev, true, buf); 402 } 403 404 static ssize_t type_show(struct device *dev, 405 struct device_attribute *attr, char *buf) 406 { 407 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 408 409 switch (this_leaf->type) { 410 case CACHE_TYPE_DATA: 411 return sprintf(buf, "Data\n"); 412 case CACHE_TYPE_INST: 413 return sprintf(buf, "Instruction\n"); 414 case CACHE_TYPE_UNIFIED: 415 return sprintf(buf, "Unified\n"); 416 default: 417 return -EINVAL; 418 } 419 } 420 421 static ssize_t allocation_policy_show(struct device *dev, 422 struct device_attribute *attr, char *buf) 423 { 424 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 425 unsigned int ci_attr = this_leaf->attributes; 426 int n = 0; 427 428 if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE)) 429 n = sprintf(buf, "ReadWriteAllocate\n"); 430 else if (ci_attr & CACHE_READ_ALLOCATE) 431 n = sprintf(buf, "ReadAllocate\n"); 432 else if (ci_attr & CACHE_WRITE_ALLOCATE) 433 n = sprintf(buf, "WriteAllocate\n"); 434 return n; 435 } 436 437 static ssize_t write_policy_show(struct device *dev, 438 struct device_attribute *attr, char *buf) 439 { 440 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 441 unsigned int ci_attr = this_leaf->attributes; 442 int n = 0; 443 444 if (ci_attr & CACHE_WRITE_THROUGH) 445 n = sprintf(buf, "WriteThrough\n"); 446 else if (ci_attr & CACHE_WRITE_BACK) 447 n = sprintf(buf, "WriteBack\n"); 448 return n; 449 } 450 451 static DEVICE_ATTR_RO(id); 452 static DEVICE_ATTR_RO(level); 453 static DEVICE_ATTR_RO(type); 454 static DEVICE_ATTR_RO(coherency_line_size); 455 static DEVICE_ATTR_RO(ways_of_associativity); 456 static DEVICE_ATTR_RO(number_of_sets); 457 static DEVICE_ATTR_RO(size); 458 static DEVICE_ATTR_RO(allocation_policy); 459 static DEVICE_ATTR_RO(write_policy); 460 static DEVICE_ATTR_RO(shared_cpu_map); 461 static DEVICE_ATTR_RO(shared_cpu_list); 462 static DEVICE_ATTR_RO(physical_line_partition); 463 464 static struct attribute *cache_default_attrs[] = { 465 &dev_attr_id.attr, 466 &dev_attr_type.attr, 467 &dev_attr_level.attr, 468 &dev_attr_shared_cpu_map.attr, 469 &dev_attr_shared_cpu_list.attr, 470 &dev_attr_coherency_line_size.attr, 471 &dev_attr_ways_of_associativity.attr, 472 &dev_attr_number_of_sets.attr, 473 &dev_attr_size.attr, 474 &dev_attr_allocation_policy.attr, 475 &dev_attr_write_policy.attr, 476 &dev_attr_physical_line_partition.attr, 477 NULL 478 }; 479 480 static umode_t 481 cache_default_attrs_is_visible(struct kobject *kobj, 482 struct attribute *attr, int unused) 483 { 484 struct device *dev = kobj_to_dev(kobj); 485 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 486 const struct cpumask *mask = &this_leaf->shared_cpu_map; 487 umode_t mode = attr->mode; 488 489 if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID)) 490 return mode; 491 if ((attr == &dev_attr_type.attr) && this_leaf->type) 492 return mode; 493 if ((attr == &dev_attr_level.attr) && this_leaf->level) 494 return mode; 495 if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask)) 496 return mode; 497 if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask)) 498 return mode; 499 if ((attr == &dev_attr_coherency_line_size.attr) && 500 this_leaf->coherency_line_size) 501 return mode; 502 if ((attr == &dev_attr_ways_of_associativity.attr) && 503 this_leaf->size) /* allow 0 = full associativity */ 504 return mode; 505 if ((attr == &dev_attr_number_of_sets.attr) && 506 this_leaf->number_of_sets) 507 return mode; 508 if ((attr == &dev_attr_size.attr) && this_leaf->size) 509 return mode; 510 if ((attr == &dev_attr_write_policy.attr) && 511 (this_leaf->attributes & CACHE_WRITE_POLICY_MASK)) 512 return mode; 513 if ((attr == &dev_attr_allocation_policy.attr) && 514 (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK)) 515 return mode; 516 if ((attr == &dev_attr_physical_line_partition.attr) && 517 this_leaf->physical_line_partition) 518 return mode; 519 520 return 0; 521 } 522 523 static const struct attribute_group cache_default_group = { 524 .attrs = cache_default_attrs, 525 .is_visible = cache_default_attrs_is_visible, 526 }; 527 528 static const struct attribute_group *cache_default_groups[] = { 529 &cache_default_group, 530 NULL, 531 }; 532 533 static const struct attribute_group *cache_private_groups[] = { 534 &cache_default_group, 535 NULL, /* Place holder for private group */ 536 NULL, 537 }; 538 539 const struct attribute_group * 540 __weak cache_get_priv_group(struct cacheinfo *this_leaf) 541 { 542 return NULL; 543 } 544 545 static const struct attribute_group ** 546 cache_get_attribute_groups(struct cacheinfo *this_leaf) 547 { 548 const struct attribute_group *priv_group = 549 cache_get_priv_group(this_leaf); 550 551 if (!priv_group) 552 return cache_default_groups; 553 554 if (!cache_private_groups[1]) 555 cache_private_groups[1] = priv_group; 556 557 return cache_private_groups; 558 } 559 560 /* Add/Remove cache interface for CPU device */ 561 static void cpu_cache_sysfs_exit(unsigned int cpu) 562 { 563 int i; 564 struct device *ci_dev; 565 566 if (per_cpu_index_dev(cpu)) { 567 for (i = 0; i < cache_leaves(cpu); i++) { 568 ci_dev = per_cache_index_dev(cpu, i); 569 if (!ci_dev) 570 continue; 571 device_unregister(ci_dev); 572 } 573 kfree(per_cpu_index_dev(cpu)); 574 per_cpu_index_dev(cpu) = NULL; 575 } 576 device_unregister(per_cpu_cache_dev(cpu)); 577 per_cpu_cache_dev(cpu) = NULL; 578 } 579 580 static int cpu_cache_sysfs_init(unsigned int cpu) 581 { 582 struct device *dev = get_cpu_device(cpu); 583 584 if (per_cpu_cacheinfo(cpu) == NULL) 585 return -ENOENT; 586 587 per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache"); 588 if (IS_ERR(per_cpu_cache_dev(cpu))) 589 return PTR_ERR(per_cpu_cache_dev(cpu)); 590 591 /* Allocate all required memory */ 592 per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu), 593 sizeof(struct device *), GFP_KERNEL); 594 if (unlikely(per_cpu_index_dev(cpu) == NULL)) 595 goto err_out; 596 597 return 0; 598 599 err_out: 600 cpu_cache_sysfs_exit(cpu); 601 return -ENOMEM; 602 } 603 604 static int cache_add_dev(unsigned int cpu) 605 { 606 unsigned int i; 607 int rc; 608 struct device *ci_dev, *parent; 609 struct cacheinfo *this_leaf; 610 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 611 const struct attribute_group **cache_groups; 612 613 rc = cpu_cache_sysfs_init(cpu); 614 if (unlikely(rc < 0)) 615 return rc; 616 617 parent = per_cpu_cache_dev(cpu); 618 for (i = 0; i < cache_leaves(cpu); i++) { 619 this_leaf = this_cpu_ci->info_list + i; 620 if (this_leaf->disable_sysfs) 621 continue; 622 cache_groups = cache_get_attribute_groups(this_leaf); 623 ci_dev = cpu_device_create(parent, this_leaf, cache_groups, 624 "index%1u", i); 625 if (IS_ERR(ci_dev)) { 626 rc = PTR_ERR(ci_dev); 627 goto err; 628 } 629 per_cache_index_dev(cpu, i) = ci_dev; 630 } 631 cpumask_set_cpu(cpu, &cache_dev_map); 632 633 return 0; 634 err: 635 cpu_cache_sysfs_exit(cpu); 636 return rc; 637 } 638 639 static int cacheinfo_cpu_online(unsigned int cpu) 640 { 641 int rc = detect_cache_attributes(cpu); 642 643 if (rc) 644 return rc; 645 rc = cache_add_dev(cpu); 646 if (rc) 647 free_cache_attributes(cpu); 648 return rc; 649 } 650 651 static int cacheinfo_cpu_pre_down(unsigned int cpu) 652 { 653 if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map)) 654 cpu_cache_sysfs_exit(cpu); 655 656 free_cache_attributes(cpu); 657 return 0; 658 } 659 660 static int __init cacheinfo_sysfs_init(void) 661 { 662 return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online", 663 cacheinfo_cpu_online, cacheinfo_cpu_pre_down); 664 } 665 device_initcall(cacheinfo_sysfs_init); 666