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