drivers/base/arch_topology.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Arch specific cpu topology information
   4  *
   5  * Copyright (C) 2016, ARM Ltd.
   6  * Written by: Juri Lelli, ARM Ltd.
   7  */
   8
   9 #include <linux/acpi.h>
  10 #include <linux/cpu.h>
  11 #include <linux/cpufreq.h>
  12 #include <linux/device.h>
  13 #include <linux/of.h>
  14 #include <linux/slab.h>
  15 #include <linux/sched/topology.h>
  16 #include <linux/cpuset.h>
  17 #include <linux/cpumask.h>
  18 #include <linux/init.h>
  19 #include <linux/rcupdate.h>
  20 #include <linux/sched.h>
  21
  22 static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data);
  23 static struct cpumask scale_freq_counters_mask;
  24 static bool scale_freq_invariant;
  25
  26 static bool supports_scale_freq_counters(const struct cpumask *cpus)
  27 {
  28         return cpumask_subset(cpus, &scale_freq_counters_mask);
  29 }
  30
  31 bool topology_scale_freq_invariant(void)
  32 {
  33         return cpufreq_supports_freq_invariance() ||
  34                supports_scale_freq_counters(cpu_online_mask);
  35 }
  36
  37 static void update_scale_freq_invariant(bool status)
  38 {
  39         if (scale_freq_invariant == status)
  40                 return;
  41
  42         /*
  43          * Task scheduler behavior depends on frequency invariance support,
  44          * either cpufreq or counter driven. If the support status changes as
  45          * a result of counter initialisation and use, retrigger the build of
  46          * scheduling domains to ensure the information is propagated properly.
  47          */
  48         if (topology_scale_freq_invariant() == status) {
  49                 scale_freq_invariant = status;
  50                 rebuild_sched_domains_energy();
  51         }
  52 }
  53
  54 void topology_set_scale_freq_source(struct scale_freq_data *data,
  55                                     const struct cpumask *cpus)
  56 {
  57         struct scale_freq_data *sfd;
  58         int cpu;
  59
  60         /*
  61          * Avoid calling rebuild_sched_domains() unnecessarily if FIE is
  62          * supported by cpufreq.
  63          */
  64         if (cpumask_empty(&scale_freq_counters_mask))
  65                 scale_freq_invariant = topology_scale_freq_invariant();
  66
  67         rcu_read_lock();
  68
  69         for_each_cpu(cpu, cpus) {
  70                 sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
  71
  72                 /* Use ARCH provided counters whenever possible */
  73                 if (!sfd || sfd->source != SCALE_FREQ_SOURCE_ARCH) {
  74                         rcu_assign_pointer(per_cpu(sft_data, cpu), data);
  75                         cpumask_set_cpu(cpu, &scale_freq_counters_mask);
  76                 }
  77         }
  78
  79         rcu_read_unlock();
  80
  81         update_scale_freq_invariant(true);
  82 }
  83 EXPORT_SYMBOL_GPL(topology_set_scale_freq_source);
  84
  85 void topology_clear_scale_freq_source(enum scale_freq_source source,
  86                                       const struct cpumask *cpus)
  87 {
  88         struct scale_freq_data *sfd;
  89         int cpu;
  90
  91         rcu_read_lock();
  92
  93         for_each_cpu(cpu, cpus) {
  94                 sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
  95
  96                 if (sfd && sfd->source == source) {
  97                         rcu_assign_pointer(per_cpu(sft_data, cpu), NULL);
  98                         cpumask_clear_cpu(cpu, &scale_freq_counters_mask);
  99                 }
 100         }
 101
 102         rcu_read_unlock();
 103
 104         /*
 105          * Make sure all references to previous sft_data are dropped to avoid
 106          * use-after-free races.
 107          */
 108         synchronize_rcu();
 109
 110         update_scale_freq_invariant(false);
 111 }
 112 EXPORT_SYMBOL_GPL(topology_clear_scale_freq_source);
 113
 114 void topology_scale_freq_tick(void)
 115 {
 116         struct scale_freq_data *sfd = rcu_dereference_sched(*this_cpu_ptr(&sft_data));
 117
 118         if (sfd)
 119                 sfd->set_freq_scale();
 120 }
 121
 122 DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
 123 EXPORT_PER_CPU_SYMBOL_GPL(arch_freq_scale);
 124
 125 void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq,
 126                              unsigned long max_freq)
 127 {
 128         unsigned long scale;
 129         int i;
 130
 131         if (WARN_ON_ONCE(!cur_freq || !max_freq))
 132                 return;
 133
 134         /*
 135          * If the use of counters for FIE is enabled, just return as we don't
 136          * want to update the scale factor with information from CPUFREQ.
 137          * Instead the scale factor will be updated from arch_scale_freq_tick.
 138          */
 139         if (supports_scale_freq_counters(cpus))
 140                 return;
 141
 142         scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;
 143
 144         for_each_cpu(i, cpus)
 145                 per_cpu(arch_freq_scale, i) = scale;
 146 }
 147
 148 DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
 149 EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);
 150
 151 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
 152 {
 153         per_cpu(cpu_scale, cpu) = capacity;
 154 }
 155
 156 DEFINE_PER_CPU(unsigned long, thermal_pressure);
 157
 158 void topology_set_thermal_pressure(const struct cpumask *cpus,
 159                                unsigned long th_pressure)
 160 {
 161         int cpu;
 162
 163         for_each_cpu(cpu, cpus)
 164                 WRITE_ONCE(per_cpu(thermal_pressure, cpu), th_pressure);
 165 }
 166 EXPORT_SYMBOL_GPL(topology_set_thermal_pressure);
 167
 168 static ssize_t cpu_capacity_show(struct device *dev,
 169                                  struct device_attribute *attr,
 170                                  char *buf)
 171 {
 172         struct cpu *cpu = container_of(dev, struct cpu, dev);
 173
 174         return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
 175 }
 176
 177 static void update_topology_flags_workfn(struct work_struct *work);
 178 static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
 179
 180 static DEVICE_ATTR_RO(cpu_capacity);
 181
 182 static int register_cpu_capacity_sysctl(void)
 183 {
 184         int i;
 185         struct device *cpu;
 186
 187         for_each_possible_cpu(i) {
 188                 cpu = get_cpu_device(i);
 189                 if (!cpu) {
 190                         pr_err("%s: too early to get CPU%d device!\n",
 191                                __func__, i);
 192                         continue;
 193                 }
 194                 device_create_file(cpu, &dev_attr_cpu_capacity);
 195         }
 196
 197         return 0;
 198 }
 199 subsys_initcall(register_cpu_capacity_sysctl);
 200
 201 static int update_topology;
 202
 203 int topology_update_cpu_topology(void)
 204 {
 205         return update_topology;
 206 }
 207
 208 /*
 209  * Updating the sched_domains can't be done directly from cpufreq callbacks
 210  * due to locking, so queue the work for later.
 211  */
 212 static void update_topology_flags_workfn(struct work_struct *work)
 213 {
 214         update_topology = 1;
 215         rebuild_sched_domains();
 216         pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
 217         update_topology = 0;
 218 }
 219
 220 static DEFINE_PER_CPU(u32, freq_factor) = 1;
 221 static u32 *raw_capacity;
 222
 223 static int free_raw_capacity(void)
 224 {
 225         kfree(raw_capacity);
 226         raw_capacity = NULL;
 227
 228         return 0;
 229 }
 230
 231 void topology_normalize_cpu_scale(void)
 232 {
 233         u64 capacity;
 234         u64 capacity_scale;
 235         int cpu;
 236
 237         if (!raw_capacity)
 238                 return;
 239
 240         capacity_scale = 1;
 241         for_each_possible_cpu(cpu) {
 242                 capacity = raw_capacity[cpu] * per_cpu(freq_factor, cpu);
 243                 capacity_scale = max(capacity, capacity_scale);
 244         }
 245
 246         pr_debug("cpu_capacity: capacity_scale=%llu\n", capacity_scale);
 247         for_each_possible_cpu(cpu) {
 248                 capacity = raw_capacity[cpu] * per_cpu(freq_factor, cpu);
 249                 capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT,
 250                         capacity_scale);
 251                 topology_set_cpu_scale(cpu, capacity);
 252                 pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
 253                         cpu, topology_get_cpu_scale(cpu));
 254         }
 255 }
 256
 257 bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
 258 {
 259         struct clk *cpu_clk;
 260         static bool cap_parsing_failed;
 261         int ret;
 262         u32 cpu_capacity;
 263
 264         if (cap_parsing_failed)
 265                 return false;
 266
 267         ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
 268                                    &cpu_capacity);
 269         if (!ret) {
 270                 if (!raw_capacity) {
 271                         raw_capacity = kcalloc(num_possible_cpus(),
 272                                                sizeof(*raw_capacity),
 273                                                GFP_KERNEL);
 274                         if (!raw_capacity) {
 275                                 cap_parsing_failed = true;
 276                                 return false;
 277                         }
 278                 }
 279                 raw_capacity[cpu] = cpu_capacity;
 280                 pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
 281                         cpu_node, raw_capacity[cpu]);
 282
 283                 /*
 284                  * Update freq_factor for calculating early boot cpu capacities.
 285                  * For non-clk CPU DVFS mechanism, there's no way to get the
 286                  * frequency value now, assuming they are running at the same
 287                  * frequency (by keeping the initial freq_factor value).
 288                  */
 289                 cpu_clk = of_clk_get(cpu_node, 0);
 290                 if (!PTR_ERR_OR_ZERO(cpu_clk)) {
 291                         per_cpu(freq_factor, cpu) =
 292                                 clk_get_rate(cpu_clk) / 1000;
 293                         clk_put(cpu_clk);
 294                 }
 295         } else {
 296                 if (raw_capacity) {
 297                         pr_err("cpu_capacity: missing %pOF raw capacity\n",
 298                                 cpu_node);
 299                         pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
 300                 }
 301                 cap_parsing_failed = true;
 302                 free_raw_capacity();
 303         }
 304
 305         return !ret;
 306 }
 307
 308 #ifdef CONFIG_CPU_FREQ
 309 static cpumask_var_t cpus_to_visit;
 310 static void parsing_done_workfn(struct work_struct *work);
 311 static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
 312
 313 static int
 314 init_cpu_capacity_callback(struct notifier_block *nb,
 315                            unsigned long val,
 316                            void *data)
 317 {
 318         struct cpufreq_policy *policy = data;
 319         int cpu;
 320
 321         if (!raw_capacity)
 322                 return 0;
 323
 324         if (val != CPUFREQ_CREATE_POLICY)
 325                 return 0;
 326
 327         pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
 328                  cpumask_pr_args(policy->related_cpus),
 329                  cpumask_pr_args(cpus_to_visit));
 330
 331         cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
 332
 333         for_each_cpu(cpu, policy->related_cpus)
 334                 per_cpu(freq_factor, cpu) = policy->cpuinfo.max_freq / 1000;
 335
 336         if (cpumask_empty(cpus_to_visit)) {
 337                 topology_normalize_cpu_scale();
 338                 schedule_work(&update_topology_flags_work);
 339                 free_raw_capacity();
 340                 pr_debug("cpu_capacity: parsing done\n");
 341                 schedule_work(&parsing_done_work);
 342         }
 343
 344         return 0;
 345 }
 346
 347 static struct notifier_block init_cpu_capacity_notifier = {
 348         .notifier_call = init_cpu_capacity_callback,
 349 };
 350
 351 static int __init register_cpufreq_notifier(void)
 352 {
 353         int ret;
 354
 355         /*
 356          * on ACPI-based systems we need to use the default cpu capacity
 357          * until we have the necessary code to parse the cpu capacity, so
 358          * skip registering cpufreq notifier.
 359          */
 360         if (!acpi_disabled || !raw_capacity)
 361                 return -EINVAL;
 362
 363         if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL))
 364                 return -ENOMEM;
 365
 366         cpumask_copy(cpus_to_visit, cpu_possible_mask);
 367
 368         ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
 369                                         CPUFREQ_POLICY_NOTIFIER);
 370
 371         if (ret)
 372                 free_cpumask_var(cpus_to_visit);
 373
 374         return ret;
 375 }
 376 core_initcall(register_cpufreq_notifier);
 377
 378 static void parsing_done_workfn(struct work_struct *work)
 379 {
 380         cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
 381                                          CPUFREQ_POLICY_NOTIFIER);
 382         free_cpumask_var(cpus_to_visit);
 383 }
 384
 385 #else
 386 core_initcall(free_raw_capacity);
 387 #endif
 388
 389 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
 390 /*
 391  * This function returns the logic cpu number of the node.
 392  * There are basically three kinds of return values:
 393  * (1) logic cpu number which is > 0.
 394  * (2) -ENODEV when the device tree(DT) node is valid and found in the DT but
 395  * there is no possible logical CPU in the kernel to match. This happens
 396  * when CONFIG_NR_CPUS is configure to be smaller than the number of
 397  * CPU nodes in DT. We need to just ignore this case.
 398  * (3) -1 if the node does not exist in the device tree
 399  */
 400 static int __init get_cpu_for_node(struct device_node *node)
 401 {
 402         struct device_node *cpu_node;
 403         int cpu;
 404
 405         cpu_node = of_parse_phandle(node, "cpu", 0);
 406         if (!cpu_node)
 407                 return -1;
 408
 409         cpu = of_cpu_node_to_id(cpu_node);
 410         if (cpu >= 0)
 411                 topology_parse_cpu_capacity(cpu_node, cpu);
 412         else
 413                 pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n",
 414                         cpu_node, cpumask_pr_args(cpu_possible_mask));
 415
 416         of_node_put(cpu_node);
 417         return cpu;
 418 }
 419
 420 static int __init parse_core(struct device_node *core, int package_id,
 421                              int core_id)
 422 {
 423         char name[20];
 424         bool leaf = true;
 425         int i = 0;
 426         int cpu;
 427         struct device_node *t;
 428
 429         do {
 430                 snprintf(name, sizeof(name), "thread%d", i);
 431                 t = of_get_child_by_name(core, name);
 432                 if (t) {
 433                         leaf = false;
 434                         cpu = get_cpu_for_node(t);
 435                         if (cpu >= 0) {
 436                                 cpu_topology[cpu].package_id = package_id;
 437                                 cpu_topology[cpu].core_id = core_id;
 438                                 cpu_topology[cpu].thread_id = i;
 439                         } else if (cpu != -ENODEV) {
 440                                 pr_err("%pOF: Can't get CPU for thread\n", t);
 441                                 of_node_put(t);
 442                                 return -EINVAL;
 443                         }
 444                         of_node_put(t);
 445                 }
 446                 i++;
 447         } while (t);
 448
 449         cpu = get_cpu_for_node(core);
 450         if (cpu >= 0) {
 451                 if (!leaf) {
 452                         pr_err("%pOF: Core has both threads and CPU\n",
 453                                core);
 454                         return -EINVAL;
 455                 }
 456
 457                 cpu_topology[cpu].package_id = package_id;
 458                 cpu_topology[cpu].core_id = core_id;
 459         } else if (leaf && cpu != -ENODEV) {
 460                 pr_err("%pOF: Can't get CPU for leaf core\n", core);
 461                 return -EINVAL;
 462         }
 463
 464         return 0;
 465 }
 466
 467 static int __init parse_cluster(struct device_node *cluster, int depth)
 468 {
 469         char name[20];
 470         bool leaf = true;
 471         bool has_cores = false;
 472         struct device_node *c;
 473         static int package_id __initdata;
 474         int core_id = 0;
 475         int i, ret;
 476
 477         /*
 478          * First check for child clusters; we currently ignore any
 479          * information about the nesting of clusters and present the
 480          * scheduler with a flat list of them.
 481          */
 482         i = 0;
 483         do {
 484                 snprintf(name, sizeof(name), "cluster%d", i);
 485                 c = of_get_child_by_name(cluster, name);
 486                 if (c) {
 487                         leaf = false;
 488                         ret = parse_cluster(c, depth + 1);
 489                         of_node_put(c);
 490                         if (ret != 0)
 491                                 return ret;
 492                 }
 493                 i++;
 494         } while (c);
 495
 496         /* Now check for cores */
 497         i = 0;
 498         do {
 499                 snprintf(name, sizeof(name), "core%d", i);
 500                 c = of_get_child_by_name(cluster, name);
 501                 if (c) {
 502                         has_cores = true;
 503
 504                         if (depth == 0) {
 505                                 pr_err("%pOF: cpu-map children should be clusters\n",
 506                                        c);
 507                                 of_node_put(c);
 508                                 return -EINVAL;
 509                         }
 510
 511                         if (leaf) {
 512                                 ret = parse_core(c, package_id, core_id++);
 513                         } else {
 514                                 pr_err("%pOF: Non-leaf cluster with core %s\n",
 515                                        cluster, name);
 516                                 ret = -EINVAL;
 517                         }
 518
 519                         of_node_put(c);
 520                         if (ret != 0)
 521                                 return ret;
 522                 }
 523                 i++;
 524         } while (c);
 525
 526         if (leaf && !has_cores)
 527                 pr_warn("%pOF: empty cluster\n", cluster);
 528
 529         if (leaf)
 530                 package_id++;
 531
 532         return 0;
 533 }
 534
 535 static int __init parse_dt_topology(void)
 536 {
 537         struct device_node *cn, *map;
 538         int ret = 0;
 539         int cpu;
 540
 541         cn = of_find_node_by_path("/cpus");
 542         if (!cn) {
 543                 pr_err("No CPU information found in DT\n");
 544                 return 0;
 545         }
 546
 547         /*
 548          * When topology is provided cpu-map is essentially a root
 549          * cluster with restricted subnodes.
 550          */
 551         map = of_get_child_by_name(cn, "cpu-map");
 552         if (!map)
 553                 goto out;
 554
 555         ret = parse_cluster(map, 0);
 556         if (ret != 0)
 557                 goto out_map;
 558
 559         topology_normalize_cpu_scale();
 560
 561         /*
 562          * Check that all cores are in the topology; the SMP code will
 563          * only mark cores described in the DT as possible.
 564          */
 565         for_each_possible_cpu(cpu)
 566                 if (cpu_topology[cpu].package_id == -1)
 567                         ret = -EINVAL;
 568
 569 out_map:
 570         of_node_put(map);
 571 out:
 572         of_node_put(cn);
 573         return ret;
 574 }
 575 #endif
 576
 577 /*
 578  * cpu topology table
 579  */
 580 struct cpu_topology cpu_topology[NR_CPUS];
 581 EXPORT_SYMBOL_GPL(cpu_topology);
 582
 583 const struct cpumask *cpu_coregroup_mask(int cpu)
 584 {
 585         const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));
 586
 587         /* Find the smaller of NUMA, core or LLC siblings */
 588         if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
 589                 /* not numa in package, lets use the package siblings */
 590                 core_mask = &cpu_topology[cpu].core_sibling;
 591         }
 592         if (cpu_topology[cpu].llc_id != -1) {
 593                 if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
 594                         core_mask = &cpu_topology[cpu].llc_sibling;
 595         }
 596
 597         return core_mask;
 598 }
 599
 600 const struct cpumask *cpu_clustergroup_mask(int cpu)
 601 {
 602         return &cpu_topology[cpu].cluster_sibling;
 603 }
 604
 605 void update_siblings_masks(unsigned int cpuid)
 606 {
 607         struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
 608         int cpu;
 609
 610         /* update core and thread sibling masks */
 611         for_each_online_cpu(cpu) {
 612                 cpu_topo = &cpu_topology[cpu];
 613
 614                 if (cpuid_topo->llc_id == cpu_topo->llc_id) {
 615                         cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
 616                         cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
 617                 }
 618
 619                 if (cpuid_topo->package_id != cpu_topo->package_id)
 620                         continue;
 621
 622                 if (cpuid_topo->cluster_id == cpu_topo->cluster_id &&
 623                     cpuid_topo->cluster_id != -1) {
 624                         cpumask_set_cpu(cpu, &cpuid_topo->cluster_sibling);
 625                         cpumask_set_cpu(cpuid, &cpu_topo->cluster_sibling);
 626                 }
 627
 628                 cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
 629                 cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
 630
 631                 if (cpuid_topo->core_id != cpu_topo->core_id)
 632                         continue;
 633
 634                 cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
 635                 cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
 636         }
 637 }
 638
 639 static void clear_cpu_topology(int cpu)
 640 {
 641         struct cpu_topology *cpu_topo = &cpu_topology[cpu];
 642
 643         cpumask_clear(&cpu_topo->llc_sibling);
 644         cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);
 645
 646         cpumask_clear(&cpu_topo->cluster_sibling);
 647         cpumask_set_cpu(cpu, &cpu_topo->cluster_sibling);
 648
 649         cpumask_clear(&cpu_topo->core_sibling);
 650         cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
 651         cpumask_clear(&cpu_topo->thread_sibling);
 652         cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
 653 }
 654
 655 void __init reset_cpu_topology(void)
 656 {
 657         unsigned int cpu;
 658
 659         for_each_possible_cpu(cpu) {
 660                 struct cpu_topology *cpu_topo = &cpu_topology[cpu];
 661
 662                 cpu_topo->thread_id = -1;
 663                 cpu_topo->core_id = -1;
 664                 cpu_topo->cluster_id = -1;
 665                 cpu_topo->package_id = -1;
 666                 cpu_topo->llc_id = -1;
 667
 668                 clear_cpu_topology(cpu);
 669         }
 670 }
 671
 672 void remove_cpu_topology(unsigned int cpu)
 673 {
 674         int sibling;
 675
 676         for_each_cpu(sibling, topology_core_cpumask(cpu))
 677                 cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
 678         for_each_cpu(sibling, topology_sibling_cpumask(cpu))
 679                 cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
 680         for_each_cpu(sibling, topology_cluster_cpumask(cpu))
 681                 cpumask_clear_cpu(cpu, topology_cluster_cpumask(sibling));
 682         for_each_cpu(sibling, topology_llc_cpumask(cpu))
 683                 cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));
 684
 685         clear_cpu_topology(cpu);
 686 }
 687
 688 __weak int __init parse_acpi_topology(void)
 689 {
 690         return 0;
 691 }
 692
 693 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
 694 void __init init_cpu_topology(void)
 695 {
 696         reset_cpu_topology();
 697
 698         /*
 699          * Discard anything that was parsed if we hit an error so we
 700          * don't use partial information.
 701          */
 702         if (parse_acpi_topology())
 703                 reset_cpu_topology();
 704         else if (of_have_populated_dt() && parse_dt_topology())
 705                 reset_cpu_topology();
 706 }
 707 #endif