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 int ct_idx; 78 79 ct_idx = get_cacheinfo_idx(this_leaf->type); 80 propname = cache_type_info[ct_idx].size_prop; 81 82 of_property_read_u32(np, propname, &this_leaf->size); 83 } 84 85 /* not cache_line_size() because that's a macro in include/linux/cache.h */ 86 static void cache_get_line_size(struct cacheinfo *this_leaf, 87 struct device_node *np) 88 { 89 int i, lim, ct_idx; 90 91 ct_idx = get_cacheinfo_idx(this_leaf->type); 92 lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props); 93 94 for (i = 0; i < lim; i++) { 95 int ret; 96 u32 line_size; 97 const char *propname; 98 99 propname = cache_type_info[ct_idx].line_size_props[i]; 100 ret = of_property_read_u32(np, propname, &line_size); 101 if (!ret) { 102 this_leaf->coherency_line_size = line_size; 103 break; 104 } 105 } 106 } 107 108 static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np) 109 { 110 const char *propname; 111 int ct_idx; 112 113 ct_idx = get_cacheinfo_idx(this_leaf->type); 114 propname = cache_type_info[ct_idx].nr_sets_prop; 115 116 of_property_read_u32(np, propname, &this_leaf->number_of_sets); 117 } 118 119 static void cache_associativity(struct cacheinfo *this_leaf) 120 { 121 unsigned int line_size = this_leaf->coherency_line_size; 122 unsigned int nr_sets = this_leaf->number_of_sets; 123 unsigned int size = this_leaf->size; 124 125 /* 126 * If the cache is fully associative, there is no need to 127 * check the other properties. 128 */ 129 if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0)) 130 this_leaf->ways_of_associativity = (size / nr_sets) / line_size; 131 } 132 133 static bool cache_node_is_unified(struct cacheinfo *this_leaf, 134 struct device_node *np) 135 { 136 return of_property_read_bool(np, "cache-unified"); 137 } 138 139 static void cache_of_set_props(struct cacheinfo *this_leaf, 140 struct device_node *np) 141 { 142 /* 143 * init_cache_level must setup the cache level correctly 144 * overriding the architecturally specified levels, so 145 * if type is NONE at this stage, it should be unified 146 */ 147 if (this_leaf->type == CACHE_TYPE_NOCACHE && 148 cache_node_is_unified(this_leaf, np)) 149 this_leaf->type = CACHE_TYPE_UNIFIED; 150 cache_size(this_leaf, np); 151 cache_get_line_size(this_leaf, np); 152 cache_nr_sets(this_leaf, np); 153 cache_associativity(this_leaf); 154 } 155 156 static int cache_setup_of_node(unsigned int cpu) 157 { 158 struct device_node *np; 159 struct cacheinfo *this_leaf; 160 struct device *cpu_dev = get_cpu_device(cpu); 161 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 162 unsigned int index = 0; 163 164 /* skip if fw_token is already populated */ 165 if (this_cpu_ci->info_list->fw_token) { 166 return 0; 167 } 168 169 if (!cpu_dev) { 170 pr_err("No cpu device for CPU %d\n", cpu); 171 return -ENODEV; 172 } 173 np = cpu_dev->of_node; 174 if (!np) { 175 pr_err("Failed to find cpu%d device node\n", cpu); 176 return -ENOENT; 177 } 178 179 while (index < cache_leaves(cpu)) { 180 this_leaf = this_cpu_ci->info_list + index; 181 if (this_leaf->level != 1) 182 np = of_find_next_cache_node(np); 183 else 184 np = of_node_get(np);/* cpu node itself */ 185 if (!np) 186 break; 187 cache_of_set_props(this_leaf, np); 188 this_leaf->fw_token = np; 189 index++; 190 } 191 192 if (index != cache_leaves(cpu)) /* not all OF nodes populated */ 193 return -ENOENT; 194 195 return 0; 196 } 197 #else 198 static inline int cache_setup_of_node(unsigned int cpu) { return 0; } 199 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, 200 struct cacheinfo *sib_leaf) 201 { 202 /* 203 * For non-DT/ACPI systems, assume unique level 1 caches, system-wide 204 * shared caches for all other levels. This will be used only if 205 * arch specific code has not populated shared_cpu_map 206 */ 207 return !(this_leaf->level == 1); 208 } 209 #endif 210 211 int __weak cache_setup_acpi(unsigned int cpu) 212 { 213 return -ENOTSUPP; 214 } 215 216 static int cache_shared_cpu_map_setup(unsigned int cpu) 217 { 218 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 219 struct cacheinfo *this_leaf, *sib_leaf; 220 unsigned int index; 221 int ret = 0; 222 223 if (this_cpu_ci->cpu_map_populated) 224 return 0; 225 226 if (of_have_populated_dt()) 227 ret = cache_setup_of_node(cpu); 228 else if (!acpi_disabled) 229 ret = cache_setup_acpi(cpu); 230 231 if (ret) 232 return ret; 233 234 for (index = 0; index < cache_leaves(cpu); index++) { 235 unsigned int i; 236 237 this_leaf = this_cpu_ci->info_list + index; 238 /* skip if shared_cpu_map is already populated */ 239 if (!cpumask_empty(&this_leaf->shared_cpu_map)) 240 continue; 241 242 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map); 243 for_each_online_cpu(i) { 244 struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i); 245 246 if (i == cpu || !sib_cpu_ci->info_list) 247 continue;/* skip if itself or no cacheinfo */ 248 sib_leaf = sib_cpu_ci->info_list + index; 249 if (cache_leaves_are_shared(this_leaf, sib_leaf)) { 250 cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map); 251 cpumask_set_cpu(i, &this_leaf->shared_cpu_map); 252 } 253 } 254 } 255 256 return 0; 257 } 258 259 static void cache_shared_cpu_map_remove(unsigned int cpu) 260 { 261 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 262 struct cacheinfo *this_leaf, *sib_leaf; 263 unsigned int sibling, index; 264 265 for (index = 0; index < cache_leaves(cpu); index++) { 266 this_leaf = this_cpu_ci->info_list + index; 267 for_each_cpu(sibling, &this_leaf->shared_cpu_map) { 268 struct cpu_cacheinfo *sib_cpu_ci; 269 270 if (sibling == cpu) /* skip itself */ 271 continue; 272 273 sib_cpu_ci = get_cpu_cacheinfo(sibling); 274 if (!sib_cpu_ci->info_list) 275 continue; 276 277 sib_leaf = sib_cpu_ci->info_list + index; 278 cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map); 279 cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map); 280 } 281 if (of_have_populated_dt()) 282 of_node_put(this_leaf->fw_token); 283 } 284 } 285 286 static void free_cache_attributes(unsigned int cpu) 287 { 288 if (!per_cpu_cacheinfo(cpu)) 289 return; 290 291 cache_shared_cpu_map_remove(cpu); 292 293 kfree(per_cpu_cacheinfo(cpu)); 294 per_cpu_cacheinfo(cpu) = NULL; 295 } 296 297 int __weak init_cache_level(unsigned int cpu) 298 { 299 return -ENOENT; 300 } 301 302 int __weak populate_cache_leaves(unsigned int cpu) 303 { 304 return -ENOENT; 305 } 306 307 static int detect_cache_attributes(unsigned int cpu) 308 { 309 int ret; 310 311 if (init_cache_level(cpu) || !cache_leaves(cpu)) 312 return -ENOENT; 313 314 per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu), 315 sizeof(struct cacheinfo), GFP_KERNEL); 316 if (per_cpu_cacheinfo(cpu) == NULL) 317 return -ENOMEM; 318 319 /* 320 * populate_cache_leaves() may completely setup the cache leaves and 321 * shared_cpu_map or it may leave it partially setup. 322 */ 323 ret = populate_cache_leaves(cpu); 324 if (ret) 325 goto free_ci; 326 /* 327 * For systems using DT for cache hierarchy, fw_token 328 * and shared_cpu_map will be set up here only if they are 329 * not populated already 330 */ 331 ret = cache_shared_cpu_map_setup(cpu); 332 if (ret) { 333 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu); 334 goto free_ci; 335 } 336 337 return 0; 338 339 free_ci: 340 free_cache_attributes(cpu); 341 return ret; 342 } 343 344 /* pointer to cpuX/cache device */ 345 static DEFINE_PER_CPU(struct device *, ci_cache_dev); 346 #define per_cpu_cache_dev(cpu) (per_cpu(ci_cache_dev, cpu)) 347 348 static cpumask_t cache_dev_map; 349 350 /* pointer to array of devices for cpuX/cache/indexY */ 351 static DEFINE_PER_CPU(struct device **, ci_index_dev); 352 #define per_cpu_index_dev(cpu) (per_cpu(ci_index_dev, cpu)) 353 #define per_cache_index_dev(cpu, idx) ((per_cpu_index_dev(cpu))[idx]) 354 355 #define show_one(file_name, object) \ 356 static ssize_t file_name##_show(struct device *dev, \ 357 struct device_attribute *attr, char *buf) \ 358 { \ 359 struct cacheinfo *this_leaf = dev_get_drvdata(dev); \ 360 return sprintf(buf, "%u\n", this_leaf->object); \ 361 } 362 363 show_one(id, id); 364 show_one(level, level); 365 show_one(coherency_line_size, coherency_line_size); 366 show_one(number_of_sets, number_of_sets); 367 show_one(physical_line_partition, physical_line_partition); 368 show_one(ways_of_associativity, ways_of_associativity); 369 370 static ssize_t size_show(struct device *dev, 371 struct device_attribute *attr, char *buf) 372 { 373 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 374 375 return sprintf(buf, "%uK\n", this_leaf->size >> 10); 376 } 377 378 static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf) 379 { 380 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 381 const struct cpumask *mask = &this_leaf->shared_cpu_map; 382 383 return cpumap_print_to_pagebuf(list, buf, mask); 384 } 385 386 static ssize_t shared_cpu_map_show(struct device *dev, 387 struct device_attribute *attr, char *buf) 388 { 389 return shared_cpumap_show_func(dev, false, buf); 390 } 391 392 static ssize_t shared_cpu_list_show(struct device *dev, 393 struct device_attribute *attr, char *buf) 394 { 395 return shared_cpumap_show_func(dev, true, buf); 396 } 397 398 static ssize_t type_show(struct device *dev, 399 struct device_attribute *attr, char *buf) 400 { 401 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 402 403 switch (this_leaf->type) { 404 case CACHE_TYPE_DATA: 405 return sprintf(buf, "Data\n"); 406 case CACHE_TYPE_INST: 407 return sprintf(buf, "Instruction\n"); 408 case CACHE_TYPE_UNIFIED: 409 return sprintf(buf, "Unified\n"); 410 default: 411 return -EINVAL; 412 } 413 } 414 415 static ssize_t allocation_policy_show(struct device *dev, 416 struct device_attribute *attr, char *buf) 417 { 418 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 419 unsigned int ci_attr = this_leaf->attributes; 420 int n = 0; 421 422 if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE)) 423 n = sprintf(buf, "ReadWriteAllocate\n"); 424 else if (ci_attr & CACHE_READ_ALLOCATE) 425 n = sprintf(buf, "ReadAllocate\n"); 426 else if (ci_attr & CACHE_WRITE_ALLOCATE) 427 n = sprintf(buf, "WriteAllocate\n"); 428 return n; 429 } 430 431 static ssize_t write_policy_show(struct device *dev, 432 struct device_attribute *attr, char *buf) 433 { 434 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 435 unsigned int ci_attr = this_leaf->attributes; 436 int n = 0; 437 438 if (ci_attr & CACHE_WRITE_THROUGH) 439 n = sprintf(buf, "WriteThrough\n"); 440 else if (ci_attr & CACHE_WRITE_BACK) 441 n = sprintf(buf, "WriteBack\n"); 442 return n; 443 } 444 445 static DEVICE_ATTR_RO(id); 446 static DEVICE_ATTR_RO(level); 447 static DEVICE_ATTR_RO(type); 448 static DEVICE_ATTR_RO(coherency_line_size); 449 static DEVICE_ATTR_RO(ways_of_associativity); 450 static DEVICE_ATTR_RO(number_of_sets); 451 static DEVICE_ATTR_RO(size); 452 static DEVICE_ATTR_RO(allocation_policy); 453 static DEVICE_ATTR_RO(write_policy); 454 static DEVICE_ATTR_RO(shared_cpu_map); 455 static DEVICE_ATTR_RO(shared_cpu_list); 456 static DEVICE_ATTR_RO(physical_line_partition); 457 458 static struct attribute *cache_default_attrs[] = { 459 &dev_attr_id.attr, 460 &dev_attr_type.attr, 461 &dev_attr_level.attr, 462 &dev_attr_shared_cpu_map.attr, 463 &dev_attr_shared_cpu_list.attr, 464 &dev_attr_coherency_line_size.attr, 465 &dev_attr_ways_of_associativity.attr, 466 &dev_attr_number_of_sets.attr, 467 &dev_attr_size.attr, 468 &dev_attr_allocation_policy.attr, 469 &dev_attr_write_policy.attr, 470 &dev_attr_physical_line_partition.attr, 471 NULL 472 }; 473 474 static umode_t 475 cache_default_attrs_is_visible(struct kobject *kobj, 476 struct attribute *attr, int unused) 477 { 478 struct device *dev = kobj_to_dev(kobj); 479 struct cacheinfo *this_leaf = dev_get_drvdata(dev); 480 const struct cpumask *mask = &this_leaf->shared_cpu_map; 481 umode_t mode = attr->mode; 482 483 if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID)) 484 return mode; 485 if ((attr == &dev_attr_type.attr) && this_leaf->type) 486 return mode; 487 if ((attr == &dev_attr_level.attr) && this_leaf->level) 488 return mode; 489 if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask)) 490 return mode; 491 if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask)) 492 return mode; 493 if ((attr == &dev_attr_coherency_line_size.attr) && 494 this_leaf->coherency_line_size) 495 return mode; 496 if ((attr == &dev_attr_ways_of_associativity.attr) && 497 this_leaf->size) /* allow 0 = full associativity */ 498 return mode; 499 if ((attr == &dev_attr_number_of_sets.attr) && 500 this_leaf->number_of_sets) 501 return mode; 502 if ((attr == &dev_attr_size.attr) && this_leaf->size) 503 return mode; 504 if ((attr == &dev_attr_write_policy.attr) && 505 (this_leaf->attributes & CACHE_WRITE_POLICY_MASK)) 506 return mode; 507 if ((attr == &dev_attr_allocation_policy.attr) && 508 (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK)) 509 return mode; 510 if ((attr == &dev_attr_physical_line_partition.attr) && 511 this_leaf->physical_line_partition) 512 return mode; 513 514 return 0; 515 } 516 517 static const struct attribute_group cache_default_group = { 518 .attrs = cache_default_attrs, 519 .is_visible = cache_default_attrs_is_visible, 520 }; 521 522 static const struct attribute_group *cache_default_groups[] = { 523 &cache_default_group, 524 NULL, 525 }; 526 527 static const struct attribute_group *cache_private_groups[] = { 528 &cache_default_group, 529 NULL, /* Place holder for private group */ 530 NULL, 531 }; 532 533 const struct attribute_group * 534 __weak cache_get_priv_group(struct cacheinfo *this_leaf) 535 { 536 return NULL; 537 } 538 539 static const struct attribute_group ** 540 cache_get_attribute_groups(struct cacheinfo *this_leaf) 541 { 542 const struct attribute_group *priv_group = 543 cache_get_priv_group(this_leaf); 544 545 if (!priv_group) 546 return cache_default_groups; 547 548 if (!cache_private_groups[1]) 549 cache_private_groups[1] = priv_group; 550 551 return cache_private_groups; 552 } 553 554 /* Add/Remove cache interface for CPU device */ 555 static void cpu_cache_sysfs_exit(unsigned int cpu) 556 { 557 int i; 558 struct device *ci_dev; 559 560 if (per_cpu_index_dev(cpu)) { 561 for (i = 0; i < cache_leaves(cpu); i++) { 562 ci_dev = per_cache_index_dev(cpu, i); 563 if (!ci_dev) 564 continue; 565 device_unregister(ci_dev); 566 } 567 kfree(per_cpu_index_dev(cpu)); 568 per_cpu_index_dev(cpu) = NULL; 569 } 570 device_unregister(per_cpu_cache_dev(cpu)); 571 per_cpu_cache_dev(cpu) = NULL; 572 } 573 574 static int cpu_cache_sysfs_init(unsigned int cpu) 575 { 576 struct device *dev = get_cpu_device(cpu); 577 578 if (per_cpu_cacheinfo(cpu) == NULL) 579 return -ENOENT; 580 581 per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache"); 582 if (IS_ERR(per_cpu_cache_dev(cpu))) 583 return PTR_ERR(per_cpu_cache_dev(cpu)); 584 585 /* Allocate all required memory */ 586 per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu), 587 sizeof(struct device *), GFP_KERNEL); 588 if (unlikely(per_cpu_index_dev(cpu) == NULL)) 589 goto err_out; 590 591 return 0; 592 593 err_out: 594 cpu_cache_sysfs_exit(cpu); 595 return -ENOMEM; 596 } 597 598 static int cache_add_dev(unsigned int cpu) 599 { 600 unsigned int i; 601 int rc; 602 struct device *ci_dev, *parent; 603 struct cacheinfo *this_leaf; 604 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 605 const struct attribute_group **cache_groups; 606 607 rc = cpu_cache_sysfs_init(cpu); 608 if (unlikely(rc < 0)) 609 return rc; 610 611 parent = per_cpu_cache_dev(cpu); 612 for (i = 0; i < cache_leaves(cpu); i++) { 613 this_leaf = this_cpu_ci->info_list + i; 614 if (this_leaf->disable_sysfs) 615 continue; 616 if (this_leaf->type == CACHE_TYPE_NOCACHE) 617 break; 618 cache_groups = cache_get_attribute_groups(this_leaf); 619 ci_dev = cpu_device_create(parent, this_leaf, cache_groups, 620 "index%1u", i); 621 if (IS_ERR(ci_dev)) { 622 rc = PTR_ERR(ci_dev); 623 goto err; 624 } 625 per_cache_index_dev(cpu, i) = ci_dev; 626 } 627 cpumask_set_cpu(cpu, &cache_dev_map); 628 629 return 0; 630 err: 631 cpu_cache_sysfs_exit(cpu); 632 return rc; 633 } 634 635 static int cacheinfo_cpu_online(unsigned int cpu) 636 { 637 int rc = detect_cache_attributes(cpu); 638 639 if (rc) 640 return rc; 641 rc = cache_add_dev(cpu); 642 if (rc) 643 free_cache_attributes(cpu); 644 return rc; 645 } 646 647 static int cacheinfo_cpu_pre_down(unsigned int cpu) 648 { 649 if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map)) 650 cpu_cache_sysfs_exit(cpu); 651 652 free_cache_attributes(cpu); 653 return 0; 654 } 655 656 static int __init cacheinfo_sysfs_init(void) 657 { 658 return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online", 659 cacheinfo_cpu_online, cacheinfo_cpu_pre_down); 660 } 661 device_initcall(cacheinfo_sysfs_init); 662