drivers/base/cacheinfo.c

   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 #define per_cpu_cacheinfo_idx(cpu, idx)         \
  29                                 (per_cpu_cacheinfo(cpu) + (idx))
  30
  31 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
  32 {
  33         return ci_cacheinfo(cpu);
  34 }
  35
  36 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
  37                                            struct cacheinfo *sib_leaf)
  38 {
  39         /*
  40          * For non DT/ACPI systems, assume unique level 1 caches,
  41          * system-wide shared caches for all other levels. This will be used
  42          * only if arch specific code has not populated shared_cpu_map
  43          */
  44         if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)))
  45                 return !(this_leaf->level == 1);
  46
  47         if ((sib_leaf->attributes & CACHE_ID) &&
  48             (this_leaf->attributes & CACHE_ID))
  49                 return sib_leaf->id == this_leaf->id;
  50
  51         return sib_leaf->fw_token == this_leaf->fw_token;
  52 }
  53
  54 bool last_level_cache_is_valid(unsigned int cpu)
  55 {
  56         struct cacheinfo *llc;
  57
  58         if (!cache_leaves(cpu))
  59                 return false;
  60
  61         llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
  62
  63         return (llc->attributes & CACHE_ID) || !!llc->fw_token;
  64
  65 }
  66
  67 bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)
  68 {
  69         struct cacheinfo *llc_x, *llc_y;
  70
  71         if (!last_level_cache_is_valid(cpu_x) ||
  72             !last_level_cache_is_valid(cpu_y))
  73                 return false;
  74
  75         llc_x = per_cpu_cacheinfo_idx(cpu_x, cache_leaves(cpu_x) - 1);
  76         llc_y = per_cpu_cacheinfo_idx(cpu_y, cache_leaves(cpu_y) - 1);
  77
  78         return cache_leaves_are_shared(llc_x, llc_y);
  79 }
  80
  81 #ifdef CONFIG_OF
  82 /* OF properties to query for a given cache type */
  83 struct cache_type_info {
  84         const char *size_prop;
  85         const char *line_size_props[2];
  86         const char *nr_sets_prop;
  87 };
  88
  89 static const struct cache_type_info cache_type_info[] = {
  90         {
  91                 .size_prop       = "cache-size",
  92                 .line_size_props = { "cache-line-size",
  93                                      "cache-block-size", },
  94                 .nr_sets_prop    = "cache-sets",
  95         }, {
  96                 .size_prop       = "i-cache-size",
  97                 .line_size_props = { "i-cache-line-size",
  98                                      "i-cache-block-size", },
  99                 .nr_sets_prop    = "i-cache-sets",
 100         }, {
 101                 .size_prop       = "d-cache-size",
 102                 .line_size_props = { "d-cache-line-size",
 103                                      "d-cache-block-size", },
 104                 .nr_sets_prop    = "d-cache-sets",
 105         },
 106 };
 107
 108 static inline int get_cacheinfo_idx(enum cache_type type)
 109 {
 110         if (type == CACHE_TYPE_UNIFIED)
 111                 return 0;
 112         return type;
 113 }
 114
 115 static void cache_size(struct cacheinfo *this_leaf, struct device_node *np)
 116 {
 117         const char *propname;
 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         of_property_read_u32(np, propname, &this_leaf->size);
 124 }
 125
 126 /* not cache_line_size() because that's a macro in include/linux/cache.h */
 127 static void cache_get_line_size(struct cacheinfo *this_leaf,
 128                                 struct device_node *np)
 129 {
 130         int i, lim, ct_idx;
 131
 132         ct_idx = get_cacheinfo_idx(this_leaf->type);
 133         lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
 134
 135         for (i = 0; i < lim; i++) {
 136                 int ret;
 137                 u32 line_size;
 138                 const char *propname;
 139
 140                 propname = cache_type_info[ct_idx].line_size_props[i];
 141                 ret = of_property_read_u32(np, propname, &line_size);
 142                 if (!ret) {
 143                         this_leaf->coherency_line_size = line_size;
 144                         break;
 145                 }
 146         }
 147 }
 148
 149 static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
 150 {
 151         const char *propname;
 152         int ct_idx;
 153
 154         ct_idx = get_cacheinfo_idx(this_leaf->type);
 155         propname = cache_type_info[ct_idx].nr_sets_prop;
 156
 157         of_property_read_u32(np, propname, &this_leaf->number_of_sets);
 158 }
 159
 160 static void cache_associativity(struct cacheinfo *this_leaf)
 161 {
 162         unsigned int line_size = this_leaf->coherency_line_size;
 163         unsigned int nr_sets = this_leaf->number_of_sets;
 164         unsigned int size = this_leaf->size;
 165
 166         /*
 167          * If the cache is fully associative, there is no need to
 168          * check the other properties.
 169          */
 170         if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
 171                 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
 172 }
 173
 174 static bool cache_node_is_unified(struct cacheinfo *this_leaf,
 175                                   struct device_node *np)
 176 {
 177         return of_property_read_bool(np, "cache-unified");
 178 }
 179
 180 static void cache_of_set_props(struct cacheinfo *this_leaf,
 181                                struct device_node *np)
 182 {
 183         /*
 184          * init_cache_level must setup the cache level correctly
 185          * overriding the architecturally specified levels, so
 186          * if type is NONE at this stage, it should be unified
 187          */
 188         if (this_leaf->type == CACHE_TYPE_NOCACHE &&
 189             cache_node_is_unified(this_leaf, np))
 190                 this_leaf->type = CACHE_TYPE_UNIFIED;
 191         cache_size(this_leaf, np);
 192         cache_get_line_size(this_leaf, np);
 193         cache_nr_sets(this_leaf, np);
 194         cache_associativity(this_leaf);
 195 }
 196
 197 static int cache_setup_of_node(unsigned int cpu)
 198 {
 199         struct device_node *np, *prev;
 200         struct cacheinfo *this_leaf;
 201         unsigned int index = 0;
 202
 203         np = of_cpu_device_node_get(cpu);
 204         if (!np) {
 205                 pr_err("Failed to find cpu%d device node\n", cpu);
 206                 return -ENOENT;
 207         }
 208
 209         prev = np;
 210
 211         while (index < cache_leaves(cpu)) {
 212                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 213                 if (this_leaf->level != 1) {
 214                         np = of_find_next_cache_node(np);
 215                         of_node_put(prev);
 216                         prev = np;
 217                         if (!np)
 218                                 break;
 219                 }
 220                 cache_of_set_props(this_leaf, np);
 221                 this_leaf->fw_token = np;
 222                 index++;
 223         }
 224
 225         of_node_put(np);
 226
 227         if (index != cache_leaves(cpu)) /* not all OF nodes populated */
 228                 return -ENOENT;
 229
 230         return 0;
 231 }
 232
 233 static int of_count_cache_leaves(struct device_node *np)
 234 {
 235         unsigned int leaves = 0;
 236
 237         if (of_property_read_bool(np, "cache-size"))
 238                 ++leaves;
 239         if (of_property_read_bool(np, "i-cache-size"))
 240                 ++leaves;
 241         if (of_property_read_bool(np, "d-cache-size"))
 242                 ++leaves;
 243
 244         if (!leaves) {
 245                 /* The '[i-|d-|]cache-size' property is required, but
 246                  * if absent, fallback on the 'cache-unified' property.
 247                  */
 248                 if (of_property_read_bool(np, "cache-unified"))
 249                         return 1;
 250                 else
 251                         return 2;
 252         }
 253
 254         return leaves;
 255 }
 256
 257 int init_of_cache_level(unsigned int cpu)
 258 {
 259         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 260         struct device_node *np = of_cpu_device_node_get(cpu);
 261         struct device_node *prev = NULL;
 262         unsigned int levels = 0, leaves, level;
 263
 264         leaves = of_count_cache_leaves(np);
 265         if (leaves > 0)
 266                 levels = 1;
 267
 268         prev = np;
 269         while ((np = of_find_next_cache_node(np))) {
 270                 of_node_put(prev);
 271                 prev = np;
 272                 if (!of_device_is_compatible(np, "cache"))
 273                         goto err_out;
 274                 if (of_property_read_u32(np, "cache-level", &level))
 275                         goto err_out;
 276                 if (level <= levels)
 277                         goto err_out;
 278
 279                 leaves += of_count_cache_leaves(np);
 280                 levels = level;
 281         }
 282
 283         of_node_put(np);
 284         this_cpu_ci->num_levels = levels;
 285         this_cpu_ci->num_leaves = leaves;
 286
 287         return 0;
 288
 289 err_out:
 290         of_node_put(np);
 291         return -EINVAL;
 292 }
 293
 294 #else
 295 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
 296 int init_of_cache_level(unsigned int cpu) { return 0; }
 297 #endif
 298
 299 int __weak cache_setup_acpi(unsigned int cpu)
 300 {
 301         return -ENOTSUPP;
 302 }
 303
 304 unsigned int coherency_max_size;
 305
 306 static int cache_setup_properties(unsigned int cpu)
 307 {
 308         int ret = 0;
 309
 310         if (of_have_populated_dt())
 311                 ret = cache_setup_of_node(cpu);
 312         else if (!acpi_disabled)
 313                 ret = cache_setup_acpi(cpu);
 314
 315         return ret;
 316 }
 317
 318 static int cache_shared_cpu_map_setup(unsigned int cpu)
 319 {
 320         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 321         struct cacheinfo *this_leaf, *sib_leaf;
 322         unsigned int index, sib_index;
 323         int ret = 0;
 324
 325         if (this_cpu_ci->cpu_map_populated)
 326                 return 0;
 327
 328         /*
 329          * skip setting up cache properties if LLC is valid, just need
 330          * to update the shared cpu_map if the cache attributes were
 331          * populated early before all the cpus are brought online
 332          */
 333         if (!last_level_cache_is_valid(cpu)) {
 334                 ret = cache_setup_properties(cpu);
 335                 if (ret)
 336                         return ret;
 337         }
 338
 339         for (index = 0; index < cache_leaves(cpu); index++) {
 340                 unsigned int i;
 341
 342                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 343
 344                 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
 345                 for_each_online_cpu(i) {
 346                         struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
 347
 348                         if (i == cpu || !sib_cpu_ci->info_list)
 349                                 continue;/* skip if itself or no cacheinfo */
 350                         for (sib_index = 0; sib_index < cache_leaves(i); sib_index++) {
 351                                 sib_leaf = per_cpu_cacheinfo_idx(i, sib_index);
 352                                 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
 353                                         cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
 354                                         cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
 355                                         break;
 356                                 }
 357                         }
 358                 }
 359                 /* record the maximum cache line size */
 360                 if (this_leaf->coherency_line_size > coherency_max_size)
 361                         coherency_max_size = this_leaf->coherency_line_size;
 362         }
 363
 364         return 0;
 365 }
 366
 367 static void cache_shared_cpu_map_remove(unsigned int cpu)
 368 {
 369         struct cacheinfo *this_leaf, *sib_leaf;
 370         unsigned int sibling, index, sib_index;
 371
 372         for (index = 0; index < cache_leaves(cpu); index++) {
 373                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 374                 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
 375                         struct cpu_cacheinfo *sib_cpu_ci =
 376                                                 get_cpu_cacheinfo(sibling);
 377
 378                         if (sibling == cpu || !sib_cpu_ci->info_list)
 379                                 continue;/* skip if itself or no cacheinfo */
 380
 381                         for (sib_index = 0; sib_index < cache_leaves(sibling); sib_index++) {
 382                                 sib_leaf = per_cpu_cacheinfo_idx(sibling, sib_index);
 383                                 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
 384                                         cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
 385                                         cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
 386                                         break;
 387                                 }
 388                         }
 389                 }
 390         }
 391 }
 392
 393 static void free_cache_attributes(unsigned int cpu)
 394 {
 395         if (!per_cpu_cacheinfo(cpu))
 396                 return;
 397
 398         cache_shared_cpu_map_remove(cpu);
 399 }
 400
 401 int __weak init_cache_level(unsigned int cpu)
 402 {
 403         return -ENOENT;
 404 }
 405
 406 int __weak populate_cache_leaves(unsigned int cpu)
 407 {
 408         return -ENOENT;
 409 }
 410
 411 static inline
 412 int allocate_cache_info(int cpu)
 413 {
 414         per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
 415                                          sizeof(struct cacheinfo), GFP_ATOMIC);
 416         if (!per_cpu_cacheinfo(cpu)) {
 417                 cache_leaves(cpu) = 0;
 418                 return -ENOMEM;
 419         }
 420
 421         return 0;
 422 }
 423
 424 int fetch_cache_info(unsigned int cpu)
 425 {
 426         struct cpu_cacheinfo *this_cpu_ci;
 427         unsigned int levels = 0, split_levels = 0;
 428         int ret;
 429
 430         if (acpi_disabled) {
 431                 ret = init_of_cache_level(cpu);
 432                 if (ret < 0)
 433                         return ret;
 434         } else {
 435                 ret = acpi_get_cache_info(cpu, &levels, &split_levels);
 436                 if (ret < 0)
 437                         return ret;
 438
 439                 this_cpu_ci = get_cpu_cacheinfo(cpu);
 440                 this_cpu_ci->num_levels = levels;
 441                 /*
 442                  * This assumes that:
 443                  * - there cannot be any split caches (data/instruction)
 444                  *   above a unified cache
 445                  * - data/instruction caches come by pair
 446                  */
 447                 this_cpu_ci->num_leaves = levels + split_levels;
 448         }
 449         if (!cache_leaves(cpu))
 450                 return -ENOENT;
 451
 452         return allocate_cache_info(cpu);
 453 }
 454
 455 int detect_cache_attributes(unsigned int cpu)
 456 {
 457         int ret;
 458
 459         /* Since early initialization/allocation of the cacheinfo is allowed
 460          * via fetch_cache_info() and this also gets called as CPU hotplug
 461          * callbacks via cacheinfo_cpu_online, the init/alloc can be skipped
 462          * as it will happen only once (the cacheinfo memory is never freed).
 463          * Just populate the cacheinfo.
 464          */
 465         if (per_cpu_cacheinfo(cpu))
 466                 goto populate_leaves;
 467
 468         if (init_cache_level(cpu) || !cache_leaves(cpu))
 469                 return -ENOENT;
 470
 471         ret = allocate_cache_info(cpu);
 472         if (ret)
 473                 return ret;
 474
 475 populate_leaves:
 476         /*
 477          * If LLC is valid the cache leaves were already populated so just go to
 478          * update the cpu map.
 479          */
 480         if (!last_level_cache_is_valid(cpu)) {
 481                 /*
 482                  * populate_cache_leaves() may completely setup the cache leaves and
 483                  * shared_cpu_map or it may leave it partially setup.
 484                  */
 485                 ret = populate_cache_leaves(cpu);
 486                 if (ret)
 487                         goto free_ci;
 488         }
 489
 490         /*
 491          * For systems using DT for cache hierarchy, fw_token
 492          * and shared_cpu_map will be set up here only if they are
 493          * not populated already
 494          */
 495         ret = cache_shared_cpu_map_setup(cpu);
 496         if (ret) {
 497                 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
 498                 goto free_ci;
 499         }
 500
 501         return 0;
 502
 503 free_ci:
 504         free_cache_attributes(cpu);
 505         return ret;
 506 }
 507
 508 /* pointer to cpuX/cache device */
 509 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
 510 #define per_cpu_cache_dev(cpu)  (per_cpu(ci_cache_dev, cpu))
 511
 512 static cpumask_t cache_dev_map;
 513
 514 /* pointer to array of devices for cpuX/cache/indexY */
 515 static DEFINE_PER_CPU(struct device **, ci_index_dev);
 516 #define per_cpu_index_dev(cpu)  (per_cpu(ci_index_dev, cpu))
 517 #define per_cache_index_dev(cpu, idx)   ((per_cpu_index_dev(cpu))[idx])
 518
 519 #define show_one(file_name, object)                             \
 520 static ssize_t file_name##_show(struct device *dev,             \
 521                 struct device_attribute *attr, char *buf)       \
 522 {                                                               \
 523         struct cacheinfo *this_leaf = dev_get_drvdata(dev);     \
 524         return sysfs_emit(buf, "%u\n", this_leaf->object);      \
 525 }
 526
 527 show_one(id, id);
 528 show_one(level, level);
 529 show_one(coherency_line_size, coherency_line_size);
 530 show_one(number_of_sets, number_of_sets);
 531 show_one(physical_line_partition, physical_line_partition);
 532 show_one(ways_of_associativity, ways_of_associativity);
 533
 534 static ssize_t size_show(struct device *dev,
 535                          struct device_attribute *attr, char *buf)
 536 {
 537         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 538
 539         return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
 540 }
 541
 542 static ssize_t shared_cpu_map_show(struct device *dev,
 543                                    struct device_attribute *attr, char *buf)
 544 {
 545         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 546         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 547
 548         return sysfs_emit(buf, "%*pb\n", nr_cpu_ids, mask);
 549 }
 550
 551 static ssize_t shared_cpu_list_show(struct device *dev,
 552                                     struct device_attribute *attr, char *buf)
 553 {
 554         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 555         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 556
 557         return sysfs_emit(buf, "%*pbl\n", nr_cpu_ids, mask);
 558 }
 559
 560 static ssize_t type_show(struct device *dev,
 561                          struct device_attribute *attr, char *buf)
 562 {
 563         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 564         const char *output;
 565
 566         switch (this_leaf->type) {
 567         case CACHE_TYPE_DATA:
 568                 output = "Data";
 569                 break;
 570         case CACHE_TYPE_INST:
 571                 output = "Instruction";
 572                 break;
 573         case CACHE_TYPE_UNIFIED:
 574                 output = "Unified";
 575                 break;
 576         default:
 577                 return -EINVAL;
 578         }
 579
 580         return sysfs_emit(buf, "%s\n", output);
 581 }
 582
 583 static ssize_t allocation_policy_show(struct device *dev,
 584                                       struct device_attribute *attr, char *buf)
 585 {
 586         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 587         unsigned int ci_attr = this_leaf->attributes;
 588         const char *output;
 589
 590         if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
 591                 output = "ReadWriteAllocate";
 592         else if (ci_attr & CACHE_READ_ALLOCATE)
 593                 output = "ReadAllocate";
 594         else if (ci_attr & CACHE_WRITE_ALLOCATE)
 595                 output = "WriteAllocate";
 596         else
 597                 return 0;
 598
 599         return sysfs_emit(buf, "%s\n", output);
 600 }
 601
 602 static ssize_t write_policy_show(struct device *dev,
 603                                  struct device_attribute *attr, char *buf)
 604 {
 605         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 606         unsigned int ci_attr = this_leaf->attributes;
 607         int n = 0;
 608
 609         if (ci_attr & CACHE_WRITE_THROUGH)
 610                 n = sysfs_emit(buf, "WriteThrough\n");
 611         else if (ci_attr & CACHE_WRITE_BACK)
 612                 n = sysfs_emit(buf, "WriteBack\n");
 613         return n;
 614 }
 615
 616 static DEVICE_ATTR_RO(id);
 617 static DEVICE_ATTR_RO(level);
 618 static DEVICE_ATTR_RO(type);
 619 static DEVICE_ATTR_RO(coherency_line_size);
 620 static DEVICE_ATTR_RO(ways_of_associativity);
 621 static DEVICE_ATTR_RO(number_of_sets);
 622 static DEVICE_ATTR_RO(size);
 623 static DEVICE_ATTR_RO(allocation_policy);
 624 static DEVICE_ATTR_RO(write_policy);
 625 static DEVICE_ATTR_RO(shared_cpu_map);
 626 static DEVICE_ATTR_RO(shared_cpu_list);
 627 static DEVICE_ATTR_RO(physical_line_partition);
 628
 629 static struct attribute *cache_default_attrs[] = {
 630         &dev_attr_id.attr,
 631         &dev_attr_type.attr,
 632         &dev_attr_level.attr,
 633         &dev_attr_shared_cpu_map.attr,
 634         &dev_attr_shared_cpu_list.attr,
 635         &dev_attr_coherency_line_size.attr,
 636         &dev_attr_ways_of_associativity.attr,
 637         &dev_attr_number_of_sets.attr,
 638         &dev_attr_size.attr,
 639         &dev_attr_allocation_policy.attr,
 640         &dev_attr_write_policy.attr,
 641         &dev_attr_physical_line_partition.attr,
 642         NULL
 643 };
 644
 645 static umode_t
 646 cache_default_attrs_is_visible(struct kobject *kobj,
 647                                struct attribute *attr, int unused)
 648 {
 649         struct device *dev = kobj_to_dev(kobj);
 650         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 651         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 652         umode_t mode = attr->mode;
 653
 654         if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
 655                 return mode;
 656         if ((attr == &dev_attr_type.attr) && this_leaf->type)
 657                 return mode;
 658         if ((attr == &dev_attr_level.attr) && this_leaf->level)
 659                 return mode;
 660         if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
 661                 return mode;
 662         if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
 663                 return mode;
 664         if ((attr == &dev_attr_coherency_line_size.attr) &&
 665             this_leaf->coherency_line_size)
 666                 return mode;
 667         if ((attr == &dev_attr_ways_of_associativity.attr) &&
 668             this_leaf->size) /* allow 0 = full associativity */
 669                 return mode;
 670         if ((attr == &dev_attr_number_of_sets.attr) &&
 671             this_leaf->number_of_sets)
 672                 return mode;
 673         if ((attr == &dev_attr_size.attr) && this_leaf->size)
 674                 return mode;
 675         if ((attr == &dev_attr_write_policy.attr) &&
 676             (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
 677                 return mode;
 678         if ((attr == &dev_attr_allocation_policy.attr) &&
 679             (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
 680                 return mode;
 681         if ((attr == &dev_attr_physical_line_partition.attr) &&
 682             this_leaf->physical_line_partition)
 683                 return mode;
 684
 685         return 0;
 686 }
 687
 688 static const struct attribute_group cache_default_group = {
 689         .attrs = cache_default_attrs,
 690         .is_visible = cache_default_attrs_is_visible,
 691 };
 692
 693 static const struct attribute_group *cache_default_groups[] = {
 694         &cache_default_group,
 695         NULL,
 696 };
 697
 698 static const struct attribute_group *cache_private_groups[] = {
 699         &cache_default_group,
 700         NULL, /* Place holder for private group */
 701         NULL,
 702 };
 703
 704 const struct attribute_group *
 705 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
 706 {
 707         return NULL;
 708 }
 709
 710 static const struct attribute_group **
 711 cache_get_attribute_groups(struct cacheinfo *this_leaf)
 712 {
 713         const struct attribute_group *priv_group =
 714                         cache_get_priv_group(this_leaf);
 715
 716         if (!priv_group)
 717                 return cache_default_groups;
 718
 719         if (!cache_private_groups[1])
 720                 cache_private_groups[1] = priv_group;
 721
 722         return cache_private_groups;
 723 }
 724
 725 /* Add/Remove cache interface for CPU device */
 726 static void cpu_cache_sysfs_exit(unsigned int cpu)
 727 {
 728         int i;
 729         struct device *ci_dev;
 730
 731         if (per_cpu_index_dev(cpu)) {
 732                 for (i = 0; i < cache_leaves(cpu); i++) {
 733                         ci_dev = per_cache_index_dev(cpu, i);
 734                         if (!ci_dev)
 735                                 continue;
 736                         device_unregister(ci_dev);
 737                 }
 738                 kfree(per_cpu_index_dev(cpu));
 739                 per_cpu_index_dev(cpu) = NULL;
 740         }
 741         device_unregister(per_cpu_cache_dev(cpu));
 742         per_cpu_cache_dev(cpu) = NULL;
 743 }
 744
 745 static int cpu_cache_sysfs_init(unsigned int cpu)
 746 {
 747         struct device *dev = get_cpu_device(cpu);
 748
 749         if (per_cpu_cacheinfo(cpu) == NULL)
 750                 return -ENOENT;
 751
 752         per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
 753         if (IS_ERR(per_cpu_cache_dev(cpu)))
 754                 return PTR_ERR(per_cpu_cache_dev(cpu));
 755
 756         /* Allocate all required memory */
 757         per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
 758                                          sizeof(struct device *), GFP_KERNEL);
 759         if (unlikely(per_cpu_index_dev(cpu) == NULL))
 760                 goto err_out;
 761
 762         return 0;
 763
 764 err_out:
 765         cpu_cache_sysfs_exit(cpu);
 766         return -ENOMEM;
 767 }
 768
 769 static int cache_add_dev(unsigned int cpu)
 770 {
 771         unsigned int i;
 772         int rc;
 773         struct device *ci_dev, *parent;
 774         struct cacheinfo *this_leaf;
 775         const struct attribute_group **cache_groups;
 776
 777         rc = cpu_cache_sysfs_init(cpu);
 778         if (unlikely(rc < 0))
 779                 return rc;
 780
 781         parent = per_cpu_cache_dev(cpu);
 782         for (i = 0; i < cache_leaves(cpu); i++) {
 783                 this_leaf = per_cpu_cacheinfo_idx(cpu, i);
 784                 if (this_leaf->disable_sysfs)
 785                         continue;
 786                 if (this_leaf->type == CACHE_TYPE_NOCACHE)
 787                         break;
 788                 cache_groups = cache_get_attribute_groups(this_leaf);
 789                 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
 790                                            "index%1u", i);
 791                 if (IS_ERR(ci_dev)) {
 792                         rc = PTR_ERR(ci_dev);
 793                         goto err;
 794                 }
 795                 per_cache_index_dev(cpu, i) = ci_dev;
 796         }
 797         cpumask_set_cpu(cpu, &cache_dev_map);
 798
 799         return 0;
 800 err:
 801         cpu_cache_sysfs_exit(cpu);
 802         return rc;
 803 }
 804
 805 static int cacheinfo_cpu_online(unsigned int cpu)
 806 {
 807         int rc = detect_cache_attributes(cpu);
 808
 809         if (rc)
 810                 return rc;
 811         rc = cache_add_dev(cpu);
 812         if (rc)
 813                 free_cache_attributes(cpu);
 814         return rc;
 815 }
 816
 817 static int cacheinfo_cpu_pre_down(unsigned int cpu)
 818 {
 819         if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
 820                 cpu_cache_sysfs_exit(cpu);
 821
 822         free_cache_attributes(cpu);
 823         return 0;
 824 }
 825
 826 static int __init cacheinfo_sysfs_init(void)
 827 {
 828         return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE,
 829                                  "base/cacheinfo:online",
 830                                  cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
 831 }
 832 device_initcall(cacheinfo_sysfs_init);