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 /* Set if no cache information is found in DT/ACPI. */
  32 static bool use_arch_info;
  33
  34 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
  35 {
  36         return ci_cacheinfo(cpu);
  37 }
  38
  39 static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
  40                                            struct cacheinfo *sib_leaf)
  41 {
  42         /*
  43          * For non DT/ACPI systems, assume unique level 1 caches,
  44          * system-wide shared caches for all other levels.
  45          */
  46         if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)) ||
  47             use_arch_info)
  48                 return (this_leaf->level != 1) && (sib_leaf->level != 1);
  49
  50         if ((sib_leaf->attributes & CACHE_ID) &&
  51             (this_leaf->attributes & CACHE_ID))
  52                 return sib_leaf->id == this_leaf->id;
  53
  54         return sib_leaf->fw_token == this_leaf->fw_token;
  55 }
  56
  57 bool last_level_cache_is_valid(unsigned int cpu)
  58 {
  59         struct cacheinfo *llc;
  60
  61         if (!cache_leaves(cpu))
  62                 return false;
  63
  64         llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
  65
  66         return (llc->attributes & CACHE_ID) || !!llc->fw_token;
  67
  68 }
  69
  70 bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)
  71 {
  72         struct cacheinfo *llc_x, *llc_y;
  73
  74         if (!last_level_cache_is_valid(cpu_x) ||
  75             !last_level_cache_is_valid(cpu_y))
  76                 return false;
  77
  78         llc_x = per_cpu_cacheinfo_idx(cpu_x, cache_leaves(cpu_x) - 1);
  79         llc_y = per_cpu_cacheinfo_idx(cpu_y, cache_leaves(cpu_y) - 1);
  80
  81         return cache_leaves_are_shared(llc_x, llc_y);
  82 }
  83
  84 #ifdef CONFIG_OF
  85
  86 static bool of_check_cache_nodes(struct device_node *np);
  87
  88 /* OF properties to query for a given cache type */
  89 struct cache_type_info {
  90         const char *size_prop;
  91         const char *line_size_props[2];
  92         const char *nr_sets_prop;
  93 };
  94
  95 static const struct cache_type_info cache_type_info[] = {
  96         {
  97                 .size_prop       = "cache-size",
  98                 .line_size_props = { "cache-line-size",
  99                                      "cache-block-size", },
 100                 .nr_sets_prop    = "cache-sets",
 101         }, {
 102                 .size_prop       = "i-cache-size",
 103                 .line_size_props = { "i-cache-line-size",
 104                                      "i-cache-block-size", },
 105                 .nr_sets_prop    = "i-cache-sets",
 106         }, {
 107                 .size_prop       = "d-cache-size",
 108                 .line_size_props = { "d-cache-line-size",
 109                                      "d-cache-block-size", },
 110                 .nr_sets_prop    = "d-cache-sets",
 111         },
 112 };
 113
 114 static inline int get_cacheinfo_idx(enum cache_type type)
 115 {
 116         if (type == CACHE_TYPE_UNIFIED)
 117                 return 0;
 118         return type;
 119 }
 120
 121 static void cache_size(struct cacheinfo *this_leaf, struct device_node *np)
 122 {
 123         const char *propname;
 124         int ct_idx;
 125
 126         ct_idx = get_cacheinfo_idx(this_leaf->type);
 127         propname = cache_type_info[ct_idx].size_prop;
 128
 129         of_property_read_u32(np, propname, &this_leaf->size);
 130 }
 131
 132 /* not cache_line_size() because that's a macro in include/linux/cache.h */
 133 static void cache_get_line_size(struct cacheinfo *this_leaf,
 134                                 struct device_node *np)
 135 {
 136         int i, lim, ct_idx;
 137
 138         ct_idx = get_cacheinfo_idx(this_leaf->type);
 139         lim = ARRAY_SIZE(cache_type_info[ct_idx].line_size_props);
 140
 141         for (i = 0; i < lim; i++) {
 142                 int ret;
 143                 u32 line_size;
 144                 const char *propname;
 145
 146                 propname = cache_type_info[ct_idx].line_size_props[i];
 147                 ret = of_property_read_u32(np, propname, &line_size);
 148                 if (!ret) {
 149                         this_leaf->coherency_line_size = line_size;
 150                         break;
 151                 }
 152         }
 153 }
 154
 155 static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
 156 {
 157         const char *propname;
 158         int ct_idx;
 159
 160         ct_idx = get_cacheinfo_idx(this_leaf->type);
 161         propname = cache_type_info[ct_idx].nr_sets_prop;
 162
 163         of_property_read_u32(np, propname, &this_leaf->number_of_sets);
 164 }
 165
 166 static void cache_associativity(struct cacheinfo *this_leaf)
 167 {
 168         unsigned int line_size = this_leaf->coherency_line_size;
 169         unsigned int nr_sets = this_leaf->number_of_sets;
 170         unsigned int size = this_leaf->size;
 171
 172         /*
 173          * If the cache is fully associative, there is no need to
 174          * check the other properties.
 175          */
 176         if (!(nr_sets == 1) && (nr_sets > 0 && size > 0 && line_size > 0))
 177                 this_leaf->ways_of_associativity = (size / nr_sets) / line_size;
 178 }
 179
 180 static bool cache_node_is_unified(struct cacheinfo *this_leaf,
 181                                   struct device_node *np)
 182 {
 183         return of_property_read_bool(np, "cache-unified");
 184 }
 185
 186 static void cache_of_set_props(struct cacheinfo *this_leaf,
 187                                struct device_node *np)
 188 {
 189         /*
 190          * init_cache_level must setup the cache level correctly
 191          * overriding the architecturally specified levels, so
 192          * if type is NONE at this stage, it should be unified
 193          */
 194         if (this_leaf->type == CACHE_TYPE_NOCACHE &&
 195             cache_node_is_unified(this_leaf, np))
 196                 this_leaf->type = CACHE_TYPE_UNIFIED;
 197         cache_size(this_leaf, np);
 198         cache_get_line_size(this_leaf, np);
 199         cache_nr_sets(this_leaf, np);
 200         cache_associativity(this_leaf);
 201 }
 202
 203 static int cache_setup_of_node(unsigned int cpu)
 204 {
 205         struct cacheinfo *this_leaf;
 206         unsigned int index = 0;
 207
 208         struct device_node *np __free(device_node) = of_cpu_device_node_get(cpu);
 209         if (!np) {
 210                 pr_err("Failed to find cpu%d device node\n", cpu);
 211                 return -ENOENT;
 212         }
 213
 214         if (!of_check_cache_nodes(np)) {
 215                 return -ENOENT;
 216         }
 217
 218         while (index < cache_leaves(cpu)) {
 219                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 220                 if (this_leaf->level != 1) {
 221                         struct device_node *prev __free(device_node) = np;
 222                         np = of_find_next_cache_node(np);
 223                         if (!np)
 224                                 break;
 225                 }
 226                 cache_of_set_props(this_leaf, np);
 227                 this_leaf->fw_token = np;
 228                 index++;
 229         }
 230
 231         if (index != cache_leaves(cpu)) /* not all OF nodes populated */
 232                 return -ENOENT;
 233
 234         return 0;
 235 }
 236
 237 static bool of_check_cache_nodes(struct device_node *np)
 238 {
 239         if (of_property_present(np, "cache-size")   ||
 240             of_property_present(np, "i-cache-size") ||
 241             of_property_present(np, "d-cache-size") ||
 242             of_property_present(np, "cache-unified"))
 243                 return true;
 244
 245         struct device_node *next __free(device_node) = of_find_next_cache_node(np);
 246         if (next) {
 247                 return true;
 248         }
 249
 250         return false;
 251 }
 252
 253 static int of_count_cache_leaves(struct device_node *np)
 254 {
 255         unsigned int leaves = 0;
 256
 257         if (of_property_present(np, "cache-size"))
 258                 ++leaves;
 259         if (of_property_present(np, "i-cache-size"))
 260                 ++leaves;
 261         if (of_property_present(np, "d-cache-size"))
 262                 ++leaves;
 263
 264         if (!leaves) {
 265                 /* The '[i-|d-|]cache-size' property is required, but
 266                  * if absent, fallback on the 'cache-unified' property.
 267                  */
 268                 if (of_property_read_bool(np, "cache-unified"))
 269                         return 1;
 270                 else
 271                         return 2;
 272         }
 273
 274         return leaves;
 275 }
 276
 277 int init_of_cache_level(unsigned int cpu)
 278 {
 279         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 280         struct device_node *np __free(device_node) = of_cpu_device_node_get(cpu);
 281         unsigned int levels = 0, leaves, level;
 282
 283         if (!of_check_cache_nodes(np)) {
 284                 return -ENOENT;
 285         }
 286
 287         leaves = of_count_cache_leaves(np);
 288         if (leaves > 0)
 289                 levels = 1;
 290
 291         while (1) {
 292                 struct device_node *prev __free(device_node) = np;
 293                 np = of_find_next_cache_node(np);
 294                 if (!np)
 295                         break;
 296
 297                 if (!of_device_is_compatible(np, "cache"))
 298                         return -EINVAL;
 299                 if (of_property_read_u32(np, "cache-level", &level))
 300                         return -EINVAL;
 301                 if (level <= levels)
 302                         return -EINVAL;
 303
 304                 leaves += of_count_cache_leaves(np);
 305                 levels = level;
 306         }
 307
 308         this_cpu_ci->num_levels = levels;
 309         this_cpu_ci->num_leaves = leaves;
 310
 311         return 0;
 312 }
 313
 314 #else
 315 static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
 316 int init_of_cache_level(unsigned int cpu) { return 0; }
 317 #endif
 318
 319 int __weak cache_setup_acpi(unsigned int cpu)
 320 {
 321         return -ENOTSUPP;
 322 }
 323
 324 unsigned int coherency_max_size;
 325
 326 static int cache_setup_properties(unsigned int cpu)
 327 {
 328         int ret = 0;
 329
 330         if (of_have_populated_dt())
 331                 ret = cache_setup_of_node(cpu);
 332         else if (!acpi_disabled)
 333                 ret = cache_setup_acpi(cpu);
 334
 335         // Assume there is no cache information available in DT/ACPI from now.
 336         if (ret && use_arch_cache_info())
 337                 use_arch_info = true;
 338
 339         return ret;
 340 }
 341
 342 static int cache_shared_cpu_map_setup(unsigned int cpu)
 343 {
 344         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 345         struct cacheinfo *this_leaf, *sib_leaf;
 346         unsigned int index, sib_index;
 347         int ret = 0;
 348
 349         if (this_cpu_ci->cpu_map_populated)
 350                 return 0;
 351
 352         /*
 353          * skip setting up cache properties if LLC is valid, just need
 354          * to update the shared cpu_map if the cache attributes were
 355          * populated early before all the cpus are brought online
 356          */
 357         if (!last_level_cache_is_valid(cpu) && !use_arch_info) {
 358                 ret = cache_setup_properties(cpu);
 359                 if (ret)
 360                         return ret;
 361         }
 362
 363         for (index = 0; index < cache_leaves(cpu); index++) {
 364                 unsigned int i;
 365
 366                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 367
 368                 cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
 369                 for_each_online_cpu(i) {
 370                         if (i == cpu || !per_cpu_cacheinfo(i))
 371                                 continue;/* skip if itself or no cacheinfo */
 372                         for (sib_index = 0; sib_index < cache_leaves(i); sib_index++) {
 373                                 sib_leaf = per_cpu_cacheinfo_idx(i, sib_index);
 374
 375                                 /*
 376                                  * Comparing cache IDs only makes sense if the leaves
 377                                  * belong to the same cache level of same type. Skip
 378                                  * the check if level and type do not match.
 379                                  */
 380                                 if (sib_leaf->level != this_leaf->level ||
 381                                     sib_leaf->type != this_leaf->type)
 382                                         continue;
 383
 384                                 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
 385                                         cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
 386                                         cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
 387                                         break;
 388                                 }
 389                         }
 390                 }
 391                 /* record the maximum cache line size */
 392                 if (this_leaf->coherency_line_size > coherency_max_size)
 393                         coherency_max_size = this_leaf->coherency_line_size;
 394         }
 395
 396         /* shared_cpu_map is now populated for the cpu */
 397         this_cpu_ci->cpu_map_populated = true;
 398         return 0;
 399 }
 400
 401 static void cache_shared_cpu_map_remove(unsigned int cpu)
 402 {
 403         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 404         struct cacheinfo *this_leaf, *sib_leaf;
 405         unsigned int sibling, index, sib_index;
 406
 407         for (index = 0; index < cache_leaves(cpu); index++) {
 408                 this_leaf = per_cpu_cacheinfo_idx(cpu, index);
 409                 for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
 410                         if (sibling == cpu || !per_cpu_cacheinfo(sibling))
 411                                 continue;/* skip if itself or no cacheinfo */
 412
 413                         for (sib_index = 0; sib_index < cache_leaves(sibling); sib_index++) {
 414                                 sib_leaf = per_cpu_cacheinfo_idx(sibling, sib_index);
 415
 416                                 /*
 417                                  * Comparing cache IDs only makes sense if the leaves
 418                                  * belong to the same cache level of same type. Skip
 419                                  * the check if level and type do not match.
 420                                  */
 421                                 if (sib_leaf->level != this_leaf->level ||
 422                                     sib_leaf->type != this_leaf->type)
 423                                         continue;
 424
 425                                 if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
 426                                         cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
 427                                         cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
 428                                         break;
 429                                 }
 430                         }
 431                 }
 432         }
 433
 434         /* cpu is no longer populated in the shared map */
 435         this_cpu_ci->cpu_map_populated = false;
 436 }
 437
 438 static void free_cache_attributes(unsigned int cpu)
 439 {
 440         if (!per_cpu_cacheinfo(cpu))
 441                 return;
 442
 443         cache_shared_cpu_map_remove(cpu);
 444 }
 445
 446 int __weak early_cache_level(unsigned int cpu)
 447 {
 448         return -ENOENT;
 449 }
 450
 451 int __weak init_cache_level(unsigned int cpu)
 452 {
 453         return -ENOENT;
 454 }
 455
 456 int __weak populate_cache_leaves(unsigned int cpu)
 457 {
 458         return -ENOENT;
 459 }
 460
 461 static inline
 462 int allocate_cache_info(int cpu)
 463 {
 464         per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
 465                                          sizeof(struct cacheinfo), GFP_ATOMIC);
 466         if (!per_cpu_cacheinfo(cpu)) {
 467                 cache_leaves(cpu) = 0;
 468                 return -ENOMEM;
 469         }
 470
 471         return 0;
 472 }
 473
 474 int fetch_cache_info(unsigned int cpu)
 475 {
 476         struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
 477         unsigned int levels = 0, split_levels = 0;
 478         int ret;
 479
 480         if (acpi_disabled) {
 481                 ret = init_of_cache_level(cpu);
 482         } else {
 483                 ret = acpi_get_cache_info(cpu, &levels, &split_levels);
 484                 if (!ret) {
 485                         this_cpu_ci->num_levels = levels;
 486                         /*
 487                          * This assumes that:
 488                          * - there cannot be any split caches (data/instruction)
 489                          *   above a unified cache
 490                          * - data/instruction caches come by pair
 491                          */
 492                         this_cpu_ci->num_leaves = levels + split_levels;
 493                 }
 494         }
 495
 496         if (ret || !cache_leaves(cpu)) {
 497                 ret = early_cache_level(cpu);
 498                 if (ret)
 499                         return ret;
 500
 501                 if (!cache_leaves(cpu))
 502                         return -ENOENT;
 503
 504                 this_cpu_ci->early_ci_levels = true;
 505         }
 506
 507         return allocate_cache_info(cpu);
 508 }
 509
 510 static inline int init_level_allocate_ci(unsigned int cpu)
 511 {
 512         unsigned int early_leaves = cache_leaves(cpu);
 513
 514         /* Since early initialization/allocation of the cacheinfo is allowed
 515          * via fetch_cache_info() and this also gets called as CPU hotplug
 516          * callbacks via cacheinfo_cpu_online, the init/alloc can be skipped
 517          * as it will happen only once (the cacheinfo memory is never freed).
 518          * Just populate the cacheinfo. However, if the cacheinfo has been
 519          * allocated early through the arch-specific early_cache_level() call,
 520          * there is a chance the info is wrong (this can happen on arm64). In
 521          * that case, call init_cache_level() anyway to give the arch-specific
 522          * code a chance to make things right.
 523          */
 524         if (per_cpu_cacheinfo(cpu) && !ci_cacheinfo(cpu)->early_ci_levels)
 525                 return 0;
 526
 527         if (init_cache_level(cpu) || !cache_leaves(cpu))
 528                 return -ENOENT;
 529
 530         /*
 531          * Now that we have properly initialized the cache level info, make
 532          * sure we don't try to do that again the next time we are called
 533          * (e.g. as CPU hotplug callbacks).
 534          */
 535         ci_cacheinfo(cpu)->early_ci_levels = false;
 536
 537         if (cache_leaves(cpu) <= early_leaves)
 538                 return 0;
 539
 540         kfree(per_cpu_cacheinfo(cpu));
 541         return allocate_cache_info(cpu);
 542 }
 543
 544 int detect_cache_attributes(unsigned int cpu)
 545 {
 546         int ret;
 547
 548         ret = init_level_allocate_ci(cpu);
 549         if (ret)
 550                 return ret;
 551
 552         /*
 553          * If LLC is valid the cache leaves were already populated so just go to
 554          * update the cpu map.
 555          */
 556         if (!last_level_cache_is_valid(cpu)) {
 557                 /*
 558                  * populate_cache_leaves() may completely setup the cache leaves and
 559                  * shared_cpu_map or it may leave it partially setup.
 560                  */
 561                 ret = populate_cache_leaves(cpu);
 562                 if (ret)
 563                         goto free_ci;
 564         }
 565
 566         /*
 567          * For systems using DT for cache hierarchy, fw_token
 568          * and shared_cpu_map will be set up here only if they are
 569          * not populated already
 570          */
 571         ret = cache_shared_cpu_map_setup(cpu);
 572         if (ret) {
 573                 pr_warn("Unable to detect cache hierarchy for CPU %d\n", cpu);
 574                 goto free_ci;
 575         }
 576
 577         return 0;
 578
 579 free_ci:
 580         free_cache_attributes(cpu);
 581         return ret;
 582 }
 583
 584 /* pointer to cpuX/cache device */
 585 static DEFINE_PER_CPU(struct device *, ci_cache_dev);
 586 #define per_cpu_cache_dev(cpu)  (per_cpu(ci_cache_dev, cpu))
 587
 588 static cpumask_t cache_dev_map;
 589
 590 /* pointer to array of devices for cpuX/cache/indexY */
 591 static DEFINE_PER_CPU(struct device **, ci_index_dev);
 592 #define per_cpu_index_dev(cpu)  (per_cpu(ci_index_dev, cpu))
 593 #define per_cache_index_dev(cpu, idx)   ((per_cpu_index_dev(cpu))[idx])
 594
 595 #define show_one(file_name, object)                             \
 596 static ssize_t file_name##_show(struct device *dev,             \
 597                 struct device_attribute *attr, char *buf)       \
 598 {                                                               \
 599         struct cacheinfo *this_leaf = dev_get_drvdata(dev);     \
 600         return sysfs_emit(buf, "%u\n", this_leaf->object);      \
 601 }
 602
 603 show_one(id, id);
 604 show_one(level, level);
 605 show_one(coherency_line_size, coherency_line_size);
 606 show_one(number_of_sets, number_of_sets);
 607 show_one(physical_line_partition, physical_line_partition);
 608 show_one(ways_of_associativity, ways_of_associativity);
 609
 610 static ssize_t size_show(struct device *dev,
 611                          struct device_attribute *attr, char *buf)
 612 {
 613         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 614
 615         return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10);
 616 }
 617
 618 static ssize_t shared_cpu_map_show(struct device *dev,
 619                                    struct device_attribute *attr, char *buf)
 620 {
 621         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 622         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 623
 624         return sysfs_emit(buf, "%*pb\n", nr_cpu_ids, mask);
 625 }
 626
 627 static ssize_t shared_cpu_list_show(struct device *dev,
 628                                     struct device_attribute *attr, char *buf)
 629 {
 630         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 631         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 632
 633         return sysfs_emit(buf, "%*pbl\n", nr_cpu_ids, mask);
 634 }
 635
 636 static ssize_t type_show(struct device *dev,
 637                          struct device_attribute *attr, char *buf)
 638 {
 639         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 640         const char *output;
 641
 642         switch (this_leaf->type) {
 643         case CACHE_TYPE_DATA:
 644                 output = "Data";
 645                 break;
 646         case CACHE_TYPE_INST:
 647                 output = "Instruction";
 648                 break;
 649         case CACHE_TYPE_UNIFIED:
 650                 output = "Unified";
 651                 break;
 652         default:
 653                 return -EINVAL;
 654         }
 655
 656         return sysfs_emit(buf, "%s\n", output);
 657 }
 658
 659 static ssize_t allocation_policy_show(struct device *dev,
 660                                       struct device_attribute *attr, char *buf)
 661 {
 662         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 663         unsigned int ci_attr = this_leaf->attributes;
 664         const char *output;
 665
 666         if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE))
 667                 output = "ReadWriteAllocate";
 668         else if (ci_attr & CACHE_READ_ALLOCATE)
 669                 output = "ReadAllocate";
 670         else if (ci_attr & CACHE_WRITE_ALLOCATE)
 671                 output = "WriteAllocate";
 672         else
 673                 return 0;
 674
 675         return sysfs_emit(buf, "%s\n", output);
 676 }
 677
 678 static ssize_t write_policy_show(struct device *dev,
 679                                  struct device_attribute *attr, char *buf)
 680 {
 681         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 682         unsigned int ci_attr = this_leaf->attributes;
 683         int n = 0;
 684
 685         if (ci_attr & CACHE_WRITE_THROUGH)
 686                 n = sysfs_emit(buf, "WriteThrough\n");
 687         else if (ci_attr & CACHE_WRITE_BACK)
 688                 n = sysfs_emit(buf, "WriteBack\n");
 689         return n;
 690 }
 691
 692 static DEVICE_ATTR_RO(id);
 693 static DEVICE_ATTR_RO(level);
 694 static DEVICE_ATTR_RO(type);
 695 static DEVICE_ATTR_RO(coherency_line_size);
 696 static DEVICE_ATTR_RO(ways_of_associativity);
 697 static DEVICE_ATTR_RO(number_of_sets);
 698 static DEVICE_ATTR_RO(size);
 699 static DEVICE_ATTR_RO(allocation_policy);
 700 static DEVICE_ATTR_RO(write_policy);
 701 static DEVICE_ATTR_RO(shared_cpu_map);
 702 static DEVICE_ATTR_RO(shared_cpu_list);
 703 static DEVICE_ATTR_RO(physical_line_partition);
 704
 705 static struct attribute *cache_default_attrs[] = {
 706         &dev_attr_id.attr,
 707         &dev_attr_type.attr,
 708         &dev_attr_level.attr,
 709         &dev_attr_shared_cpu_map.attr,
 710         &dev_attr_shared_cpu_list.attr,
 711         &dev_attr_coherency_line_size.attr,
 712         &dev_attr_ways_of_associativity.attr,
 713         &dev_attr_number_of_sets.attr,
 714         &dev_attr_size.attr,
 715         &dev_attr_allocation_policy.attr,
 716         &dev_attr_write_policy.attr,
 717         &dev_attr_physical_line_partition.attr,
 718         NULL
 719 };
 720
 721 static umode_t
 722 cache_default_attrs_is_visible(struct kobject *kobj,
 723                                struct attribute *attr, int unused)
 724 {
 725         struct device *dev = kobj_to_dev(kobj);
 726         struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 727         const struct cpumask *mask = &this_leaf->shared_cpu_map;
 728         umode_t mode = attr->mode;
 729
 730         if ((attr == &dev_attr_id.attr) && (this_leaf->attributes & CACHE_ID))
 731                 return mode;
 732         if ((attr == &dev_attr_type.attr) && this_leaf->type)
 733                 return mode;
 734         if ((attr == &dev_attr_level.attr) && this_leaf->level)
 735                 return mode;
 736         if ((attr == &dev_attr_shared_cpu_map.attr) && !cpumask_empty(mask))
 737                 return mode;
 738         if ((attr == &dev_attr_shared_cpu_list.attr) && !cpumask_empty(mask))
 739                 return mode;
 740         if ((attr == &dev_attr_coherency_line_size.attr) &&
 741             this_leaf->coherency_line_size)
 742                 return mode;
 743         if ((attr == &dev_attr_ways_of_associativity.attr) &&
 744             this_leaf->size) /* allow 0 = full associativity */
 745                 return mode;
 746         if ((attr == &dev_attr_number_of_sets.attr) &&
 747             this_leaf->number_of_sets)
 748                 return mode;
 749         if ((attr == &dev_attr_size.attr) && this_leaf->size)
 750                 return mode;
 751         if ((attr == &dev_attr_write_policy.attr) &&
 752             (this_leaf->attributes & CACHE_WRITE_POLICY_MASK))
 753                 return mode;
 754         if ((attr == &dev_attr_allocation_policy.attr) &&
 755             (this_leaf->attributes & CACHE_ALLOCATE_POLICY_MASK))
 756                 return mode;
 757         if ((attr == &dev_attr_physical_line_partition.attr) &&
 758             this_leaf->physical_line_partition)
 759                 return mode;
 760
 761         return 0;
 762 }
 763
 764 static const struct attribute_group cache_default_group = {
 765         .attrs = cache_default_attrs,
 766         .is_visible = cache_default_attrs_is_visible,
 767 };
 768
 769 static const struct attribute_group *cache_default_groups[] = {
 770         &cache_default_group,
 771         NULL,
 772 };
 773
 774 static const struct attribute_group *cache_private_groups[] = {
 775         &cache_default_group,
 776         NULL, /* Place holder for private group */
 777         NULL,
 778 };
 779
 780 const struct attribute_group *
 781 __weak cache_get_priv_group(struct cacheinfo *this_leaf)
 782 {
 783         return NULL;
 784 }
 785
 786 static const struct attribute_group **
 787 cache_get_attribute_groups(struct cacheinfo *this_leaf)
 788 {
 789         const struct attribute_group *priv_group =
 790                         cache_get_priv_group(this_leaf);
 791
 792         if (!priv_group)
 793                 return cache_default_groups;
 794
 795         if (!cache_private_groups[1])
 796                 cache_private_groups[1] = priv_group;
 797
 798         return cache_private_groups;
 799 }
 800
 801 /* Add/Remove cache interface for CPU device */
 802 static void cpu_cache_sysfs_exit(unsigned int cpu)
 803 {
 804         int i;
 805         struct device *ci_dev;
 806
 807         if (per_cpu_index_dev(cpu)) {
 808                 for (i = 0; i < cache_leaves(cpu); i++) {
 809                         ci_dev = per_cache_index_dev(cpu, i);
 810                         if (!ci_dev)
 811                                 continue;
 812                         device_unregister(ci_dev);
 813                 }
 814                 kfree(per_cpu_index_dev(cpu));
 815                 per_cpu_index_dev(cpu) = NULL;
 816         }
 817         device_unregister(per_cpu_cache_dev(cpu));
 818         per_cpu_cache_dev(cpu) = NULL;
 819 }
 820
 821 static int cpu_cache_sysfs_init(unsigned int cpu)
 822 {
 823         struct device *dev = get_cpu_device(cpu);
 824
 825         if (per_cpu_cacheinfo(cpu) == NULL)
 826                 return -ENOENT;
 827
 828         per_cpu_cache_dev(cpu) = cpu_device_create(dev, NULL, NULL, "cache");
 829         if (IS_ERR(per_cpu_cache_dev(cpu)))
 830                 return PTR_ERR(per_cpu_cache_dev(cpu));
 831
 832         /* Allocate all required memory */
 833         per_cpu_index_dev(cpu) = kcalloc(cache_leaves(cpu),
 834                                          sizeof(struct device *), GFP_KERNEL);
 835         if (unlikely(per_cpu_index_dev(cpu) == NULL))
 836                 goto err_out;
 837
 838         return 0;
 839
 840 err_out:
 841         cpu_cache_sysfs_exit(cpu);
 842         return -ENOMEM;
 843 }
 844
 845 static int cache_add_dev(unsigned int cpu)
 846 {
 847         unsigned int i;
 848         int rc;
 849         struct device *ci_dev, *parent;
 850         struct cacheinfo *this_leaf;
 851         const struct attribute_group **cache_groups;
 852
 853         rc = cpu_cache_sysfs_init(cpu);
 854         if (unlikely(rc < 0))
 855                 return rc;
 856
 857         parent = per_cpu_cache_dev(cpu);
 858         for (i = 0; i < cache_leaves(cpu); i++) {
 859                 this_leaf = per_cpu_cacheinfo_idx(cpu, i);
 860                 if (this_leaf->disable_sysfs)
 861                         continue;
 862                 if (this_leaf->type == CACHE_TYPE_NOCACHE)
 863                         break;
 864                 cache_groups = cache_get_attribute_groups(this_leaf);
 865                 ci_dev = cpu_device_create(parent, this_leaf, cache_groups,
 866                                            "index%1u", i);
 867                 if (IS_ERR(ci_dev)) {
 868                         rc = PTR_ERR(ci_dev);
 869                         goto err;
 870                 }
 871                 per_cache_index_dev(cpu, i) = ci_dev;
 872         }
 873         cpumask_set_cpu(cpu, &cache_dev_map);
 874
 875         return 0;
 876 err:
 877         cpu_cache_sysfs_exit(cpu);
 878         return rc;
 879 }
 880
 881 static unsigned int cpu_map_shared_cache(bool online, unsigned int cpu,
 882                                          cpumask_t **map)
 883 {
 884         struct cacheinfo *llc, *sib_llc;
 885         unsigned int sibling;
 886
 887         if (!last_level_cache_is_valid(cpu))
 888                 return 0;
 889
 890         llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
 891
 892         if (llc->type != CACHE_TYPE_DATA && llc->type != CACHE_TYPE_UNIFIED)
 893                 return 0;
 894
 895         if (online) {
 896                 *map = &llc->shared_cpu_map;
 897                 return cpumask_weight(*map);
 898         }
 899
 900         /* shared_cpu_map of offlined CPU will be cleared, so use sibling map */
 901         for_each_cpu(sibling, &llc->shared_cpu_map) {
 902                 if (sibling == cpu || !last_level_cache_is_valid(sibling))
 903                         continue;
 904                 sib_llc = per_cpu_cacheinfo_idx(sibling, cache_leaves(sibling) - 1);
 905                 *map = &sib_llc->shared_cpu_map;
 906                 return cpumask_weight(*map);
 907         }
 908
 909         return 0;
 910 }
 911
 912 /*
 913  * Calculate the size of the per-CPU data cache slice.  This can be
 914  * used to estimate the size of the data cache slice that can be used
 915  * by one CPU under ideal circumstances.  UNIFIED caches are counted
 916  * in addition to DATA caches.  So, please consider code cache usage
 917  * when use the result.
 918  *
 919  * Because the cache inclusive/non-inclusive information isn't
 920  * available, we just use the size of the per-CPU slice of LLC to make
 921  * the result more predictable across architectures.
 922  */
 923 static void update_per_cpu_data_slice_size_cpu(unsigned int cpu)
 924 {
 925         struct cpu_cacheinfo *ci;
 926         struct cacheinfo *llc;
 927         unsigned int nr_shared;
 928
 929         if (!last_level_cache_is_valid(cpu))
 930                 return;
 931
 932         ci = ci_cacheinfo(cpu);
 933         llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
 934
 935         if (llc->type != CACHE_TYPE_DATA && llc->type != CACHE_TYPE_UNIFIED)
 936                 return;
 937
 938         nr_shared = cpumask_weight(&llc->shared_cpu_map);
 939         if (nr_shared)
 940                 ci->per_cpu_data_slice_size = llc->size / nr_shared;
 941 }
 942
 943 static void update_per_cpu_data_slice_size(bool cpu_online, unsigned int cpu,
 944                                            cpumask_t *cpu_map)
 945 {
 946         unsigned int icpu;
 947
 948         for_each_cpu(icpu, cpu_map) {
 949                 if (!cpu_online && icpu == cpu)
 950                         continue;
 951                 update_per_cpu_data_slice_size_cpu(icpu);
 952                 setup_pcp_cacheinfo(icpu);
 953         }
 954 }
 955
 956 static int cacheinfo_cpu_online(unsigned int cpu)
 957 {
 958         int rc = detect_cache_attributes(cpu);
 959         cpumask_t *cpu_map;
 960
 961         if (rc)
 962                 return rc;
 963         rc = cache_add_dev(cpu);
 964         if (rc)
 965                 goto err;
 966         if (cpu_map_shared_cache(true, cpu, &cpu_map))
 967                 update_per_cpu_data_slice_size(true, cpu, cpu_map);
 968         return 0;
 969 err:
 970         free_cache_attributes(cpu);
 971         return rc;
 972 }
 973
 974 static int cacheinfo_cpu_pre_down(unsigned int cpu)
 975 {
 976         cpumask_t *cpu_map;
 977         unsigned int nr_shared;
 978
 979         nr_shared = cpu_map_shared_cache(false, cpu, &cpu_map);
 980         if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
 981                 cpu_cache_sysfs_exit(cpu);
 982
 983         free_cache_attributes(cpu);
 984         if (nr_shared > 1)
 985                 update_per_cpu_data_slice_size(false, cpu, cpu_map);
 986         return 0;
 987 }
 988
 989 static int __init cacheinfo_sysfs_init(void)
 990 {
 991         return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE,
 992                                  "base/cacheinfo:online",
 993                                  cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
 994 }
 995 device_initcall(cacheinfo_sysfs_init);