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 static DEFINE_PER_CPU(u32, freq_factor) = 1;
  26
  27 static bool supports_scale_freq_counters(const struct cpumask *cpus)
  28 {
  29         return cpumask_subset(cpus, &scale_freq_counters_mask);
  30 }
  31
  32 bool topology_scale_freq_invariant(void)
  33 {
  34         return cpufreq_supports_freq_invariance() ||
  35                supports_scale_freq_counters(cpu_online_mask);
  36 }
  37
  38 static void update_scale_freq_invariant(bool status)
  39 {
  40         if (scale_freq_invariant == status)
  41                 return;
  42
  43         /*
  44          * Task scheduler behavior depends on frequency invariance support,
  45          * either cpufreq or counter driven. If the support status changes as
  46          * a result of counter initialisation and use, retrigger the build of
  47          * scheduling domains to ensure the information is propagated properly.
  48          */
  49         if (topology_scale_freq_invariant() == status) {
  50                 scale_freq_invariant = status;
  51                 rebuild_sched_domains_energy();
  52         }
  53 }
  54
  55 void topology_set_scale_freq_source(struct scale_freq_data *data,
  56                                     const struct cpumask *cpus)
  57 {
  58         struct scale_freq_data *sfd;
  59         int cpu;
  60
  61         /*
  62          * Avoid calling rebuild_sched_domains() unnecessarily if FIE is
  63          * supported by cpufreq.
  64          */
  65         if (cpumask_empty(&scale_freq_counters_mask))
  66                 scale_freq_invariant = topology_scale_freq_invariant();
  67
  68         rcu_read_lock();
  69
  70         for_each_cpu(cpu, cpus) {
  71                 sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
  72
  73                 /* Use ARCH provided counters whenever possible */
  74                 if (!sfd || sfd->source != SCALE_FREQ_SOURCE_ARCH) {
  75                         rcu_assign_pointer(per_cpu(sft_data, cpu), data);
  76                         cpumask_set_cpu(cpu, &scale_freq_counters_mask);
  77                 }
  78         }
  79
  80         rcu_read_unlock();
  81
  82         update_scale_freq_invariant(true);
  83 }
  84 EXPORT_SYMBOL_GPL(topology_set_scale_freq_source);
  85
  86 void topology_clear_scale_freq_source(enum scale_freq_source source,
  87                                       const struct cpumask *cpus)
  88 {
  89         struct scale_freq_data *sfd;
  90         int cpu;
  91
  92         rcu_read_lock();
  93
  94         for_each_cpu(cpu, cpus) {
  95                 sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
  96
  97                 if (sfd && sfd->source == source) {
  98                         rcu_assign_pointer(per_cpu(sft_data, cpu), NULL);
  99                         cpumask_clear_cpu(cpu, &scale_freq_counters_mask);
 100                 }
 101         }
 102
 103         rcu_read_unlock();
 104
 105         /*
 106          * Make sure all references to previous sft_data are dropped to avoid
 107          * use-after-free races.
 108          */
 109         synchronize_rcu();
 110
 111         update_scale_freq_invariant(false);
 112 }
 113 EXPORT_SYMBOL_GPL(topology_clear_scale_freq_source);
 114
 115 void topology_scale_freq_tick(void)
 116 {
 117         struct scale_freq_data *sfd = rcu_dereference_sched(*this_cpu_ptr(&sft_data));
 118
 119         if (sfd)
 120                 sfd->set_freq_scale();
 121 }
 122
 123 DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
 124 EXPORT_PER_CPU_SYMBOL_GPL(arch_freq_scale);
 125
 126 void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq,
 127                              unsigned long max_freq)
 128 {
 129         unsigned long scale;
 130         int i;
 131
 132         if (WARN_ON_ONCE(!cur_freq || !max_freq))
 133                 return;
 134
 135         /*
 136          * If the use of counters for FIE is enabled, just return as we don't
 137          * want to update the scale factor with information from CPUFREQ.
 138          * Instead the scale factor will be updated from arch_scale_freq_tick.
 139          */
 140         if (supports_scale_freq_counters(cpus))
 141                 return;
 142
 143         scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;
 144
 145         for_each_cpu(i, cpus)
 146                 per_cpu(arch_freq_scale, i) = scale;
 147 }
 148
 149 DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
 150 EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);
 151
 152 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
 153 {
 154         per_cpu(cpu_scale, cpu) = capacity;
 155 }
 156
 157 DEFINE_PER_CPU(unsigned long, thermal_pressure);
 158
 159 /**
 160  * topology_update_thermal_pressure() - Update thermal pressure for CPUs
 161  * @cpus        : The related CPUs for which capacity has been reduced
 162  * @capped_freq : The maximum allowed frequency that CPUs can run at
 163  *
 164  * Update the value of thermal pressure for all @cpus in the mask. The
 165  * cpumask should include all (online+offline) affected CPUs, to avoid
 166  * operating on stale data when hot-plug is used for some CPUs. The
 167  * @capped_freq reflects the currently allowed max CPUs frequency due to
 168  * thermal capping. It might be also a boost frequency value, which is bigger
 169  * than the internal 'freq_factor' max frequency. In such case the pressure
 170  * value should simply be removed, since this is an indication that there is
 171  * no thermal throttling. The @capped_freq must be provided in kHz.
 172  */
 173 void topology_update_thermal_pressure(const struct cpumask *cpus,
 174                                       unsigned long capped_freq)
 175 {
 176         unsigned long max_capacity, capacity, th_pressure;
 177         u32 max_freq;
 178         int cpu;
 179
 180         cpu = cpumask_first(cpus);
 181         max_capacity = arch_scale_cpu_capacity(cpu);
 182         max_freq = per_cpu(freq_factor, cpu);
 183
 184         /* Convert to MHz scale which is used in 'freq_factor' */
 185         capped_freq /= 1000;
 186
 187         /*
 188          * Handle properly the boost frequencies, which should simply clean
 189          * the thermal pressure value.
 190          */
 191         if (max_freq <= capped_freq)
 192                 capacity = max_capacity;
 193         else
 194                 capacity = mult_frac(max_capacity, capped_freq, max_freq);
 195
 196         th_pressure = max_capacity - capacity;
 197
 198         for_each_cpu(cpu, cpus)
 199                 WRITE_ONCE(per_cpu(thermal_pressure, cpu), th_pressure);
 200 }
 201 EXPORT_SYMBOL_GPL(topology_update_thermal_pressure);
 202
 203 static ssize_t cpu_capacity_show(struct device *dev,
 204                                  struct device_attribute *attr,
 205                                  char *buf)
 206 {
 207         struct cpu *cpu = container_of(dev, struct cpu, dev);
 208
 209         return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
 210 }
 211
 212 static void update_topology_flags_workfn(struct work_struct *work);
 213 static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
 214
 215 static DEVICE_ATTR_RO(cpu_capacity);
 216
 217 static int register_cpu_capacity_sysctl(void)
 218 {
 219         int i;
 220         struct device *cpu;
 221
 222         for_each_possible_cpu(i) {
 223                 cpu = get_cpu_device(i);
 224                 if (!cpu) {
 225                         pr_err("%s: too early to get CPU%d device!\n",
 226                                __func__, i);
 227                         continue;
 228                 }
 229                 device_create_file(cpu, &dev_attr_cpu_capacity);
 230         }
 231
 232         return 0;
 233 }
 234 subsys_initcall(register_cpu_capacity_sysctl);
 235
 236 static int update_topology;
 237
 238 int topology_update_cpu_topology(void)
 239 {
 240         return update_topology;
 241 }
 242
 243 /*
 244  * Updating the sched_domains can't be done directly from cpufreq callbacks
 245  * due to locking, so queue the work for later.
 246  */
 247 static void update_topology_flags_workfn(struct work_struct *work)
 248 {
 249         update_topology = 1;
 250         rebuild_sched_domains();
 251         pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
 252         update_topology = 0;
 253 }
 254
 255 static u32 *raw_capacity;
 256
 257 static int free_raw_capacity(void)
 258 {
 259         kfree(raw_capacity);
 260         raw_capacity = NULL;
 261
 262         return 0;
 263 }
 264
 265 void topology_normalize_cpu_scale(void)
 266 {
 267         u64 capacity;
 268         u64 capacity_scale;
 269         int cpu;
 270
 271         if (!raw_capacity)
 272                 return;
 273
 274         capacity_scale = 1;
 275         for_each_possible_cpu(cpu) {
 276                 capacity = raw_capacity[cpu] * per_cpu(freq_factor, cpu);
 277                 capacity_scale = max(capacity, capacity_scale);
 278         }
 279
 280         pr_debug("cpu_capacity: capacity_scale=%llu\n", capacity_scale);
 281         for_each_possible_cpu(cpu) {
 282                 capacity = raw_capacity[cpu] * per_cpu(freq_factor, cpu);
 283                 capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT,
 284                         capacity_scale);
 285                 topology_set_cpu_scale(cpu, capacity);
 286                 pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
 287                         cpu, topology_get_cpu_scale(cpu));
 288         }
 289 }
 290
 291 bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
 292 {
 293         struct clk *cpu_clk;
 294         static bool cap_parsing_failed;
 295         int ret;
 296         u32 cpu_capacity;
 297
 298         if (cap_parsing_failed)
 299                 return false;
 300
 301         ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
 302                                    &cpu_capacity);
 303         if (!ret) {
 304                 if (!raw_capacity) {
 305                         raw_capacity = kcalloc(num_possible_cpus(),
 306                                                sizeof(*raw_capacity),
 307                                                GFP_KERNEL);
 308                         if (!raw_capacity) {
 309                                 cap_parsing_failed = true;
 310                                 return false;
 311                         }
 312                 }
 313                 raw_capacity[cpu] = cpu_capacity;
 314                 pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
 315                         cpu_node, raw_capacity[cpu]);
 316
 317                 /*
 318                  * Update freq_factor for calculating early boot cpu capacities.
 319                  * For non-clk CPU DVFS mechanism, there's no way to get the
 320                  * frequency value now, assuming they are running at the same
 321                  * frequency (by keeping the initial freq_factor value).
 322                  */
 323                 cpu_clk = of_clk_get(cpu_node, 0);
 324                 if (!PTR_ERR_OR_ZERO(cpu_clk)) {
 325                         per_cpu(freq_factor, cpu) =
 326                                 clk_get_rate(cpu_clk) / 1000;
 327                         clk_put(cpu_clk);
 328                 }
 329         } else {
 330                 if (raw_capacity) {
 331                         pr_err("cpu_capacity: missing %pOF raw capacity\n",
 332                                 cpu_node);
 333                         pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
 334                 }
 335                 cap_parsing_failed = true;
 336                 free_raw_capacity();
 337         }
 338
 339         return !ret;
 340 }
 341
 342 #ifdef CONFIG_CPU_FREQ
 343 static cpumask_var_t cpus_to_visit;
 344 static void parsing_done_workfn(struct work_struct *work);
 345 static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
 346
 347 static int
 348 init_cpu_capacity_callback(struct notifier_block *nb,
 349                            unsigned long val,
 350                            void *data)
 351 {
 352         struct cpufreq_policy *policy = data;
 353         int cpu;
 354
 355         if (!raw_capacity)
 356                 return 0;
 357
 358         if (val != CPUFREQ_CREATE_POLICY)
 359                 return 0;
 360
 361         pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
 362                  cpumask_pr_args(policy->related_cpus),
 363                  cpumask_pr_args(cpus_to_visit));
 364
 365         cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
 366
 367         for_each_cpu(cpu, policy->related_cpus)
 368                 per_cpu(freq_factor, cpu) = policy->cpuinfo.max_freq / 1000;
 369
 370         if (cpumask_empty(cpus_to_visit)) {
 371                 topology_normalize_cpu_scale();
 372                 schedule_work(&update_topology_flags_work);
 373                 free_raw_capacity();
 374                 pr_debug("cpu_capacity: parsing done\n");
 375                 schedule_work(&parsing_done_work);
 376         }
 377
 378         return 0;
 379 }
 380
 381 static struct notifier_block init_cpu_capacity_notifier = {
 382         .notifier_call = init_cpu_capacity_callback,
 383 };
 384
 385 static int __init register_cpufreq_notifier(void)
 386 {
 387         int ret;
 388
 389         /*
 390          * on ACPI-based systems we need to use the default cpu capacity
 391          * until we have the necessary code to parse the cpu capacity, so
 392          * skip registering cpufreq notifier.
 393          */
 394         if (!acpi_disabled || !raw_capacity)
 395                 return -EINVAL;
 396
 397         if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL))
 398                 return -ENOMEM;
 399
 400         cpumask_copy(cpus_to_visit, cpu_possible_mask);
 401
 402         ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
 403                                         CPUFREQ_POLICY_NOTIFIER);
 404
 405         if (ret)
 406                 free_cpumask_var(cpus_to_visit);
 407
 408         return ret;
 409 }
 410 core_initcall(register_cpufreq_notifier);
 411
 412 static void parsing_done_workfn(struct work_struct *work)
 413 {
 414         cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
 415                                          CPUFREQ_POLICY_NOTIFIER);
 416         free_cpumask_var(cpus_to_visit);
 417 }
 418
 419 #else
 420 core_initcall(free_raw_capacity);
 421 #endif
 422
 423 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
 424 /*
 425  * This function returns the logic cpu number of the node.
 426  * There are basically three kinds of return values:
 427  * (1) logic cpu number which is > 0.
 428  * (2) -ENODEV when the device tree(DT) node is valid and found in the DT but
 429  * there is no possible logical CPU in the kernel to match. This happens
 430  * when CONFIG_NR_CPUS is configure to be smaller than the number of
 431  * CPU nodes in DT. We need to just ignore this case.
 432  * (3) -1 if the node does not exist in the device tree
 433  */
 434 static int __init get_cpu_for_node(struct device_node *node)
 435 {
 436         struct device_node *cpu_node;
 437         int cpu;
 438
 439         cpu_node = of_parse_phandle(node, "cpu", 0);
 440         if (!cpu_node)
 441                 return -1;
 442
 443         cpu = of_cpu_node_to_id(cpu_node);
 444         if (cpu >= 0)
 445                 topology_parse_cpu_capacity(cpu_node, cpu);
 446         else
 447                 pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n",
 448                         cpu_node, cpumask_pr_args(cpu_possible_mask));
 449
 450         of_node_put(cpu_node);
 451         return cpu;
 452 }
 453
 454 static int __init parse_core(struct device_node *core, int package_id,
 455                              int core_id)
 456 {
 457         char name[20];
 458         bool leaf = true;
 459         int i = 0;
 460         int cpu;
 461         struct device_node *t;
 462
 463         do {
 464                 snprintf(name, sizeof(name), "thread%d", i);
 465                 t = of_get_child_by_name(core, name);
 466                 if (t) {
 467                         leaf = false;
 468                         cpu = get_cpu_for_node(t);
 469                         if (cpu >= 0) {
 470                                 cpu_topology[cpu].package_id = package_id;
 471                                 cpu_topology[cpu].core_id = core_id;
 472                                 cpu_topology[cpu].thread_id = i;
 473                         } else if (cpu != -ENODEV) {
 474                                 pr_err("%pOF: Can't get CPU for thread\n", t);
 475                                 of_node_put(t);
 476                                 return -EINVAL;
 477                         }
 478                         of_node_put(t);
 479                 }
 480                 i++;
 481         } while (t);
 482
 483         cpu = get_cpu_for_node(core);
 484         if (cpu >= 0) {
 485                 if (!leaf) {
 486                         pr_err("%pOF: Core has both threads and CPU\n",
 487                                core);
 488                         return -EINVAL;
 489                 }
 490
 491                 cpu_topology[cpu].package_id = package_id;
 492                 cpu_topology[cpu].core_id = core_id;
 493         } else if (leaf && cpu != -ENODEV) {
 494                 pr_err("%pOF: Can't get CPU for leaf core\n", core);
 495                 return -EINVAL;
 496         }
 497
 498         return 0;
 499 }
 500
 501 static int __init parse_cluster(struct device_node *cluster, int depth)
 502 {
 503         char name[20];
 504         bool leaf = true;
 505         bool has_cores = false;
 506         struct device_node *c;
 507         static int package_id __initdata;
 508         int core_id = 0;
 509         int i, ret;
 510
 511         /*
 512          * First check for child clusters; we currently ignore any
 513          * information about the nesting of clusters and present the
 514          * scheduler with a flat list of them.
 515          */
 516         i = 0;
 517         do {
 518                 snprintf(name, sizeof(name), "cluster%d", i);
 519                 c = of_get_child_by_name(cluster, name);
 520                 if (c) {
 521                         leaf = false;
 522                         ret = parse_cluster(c, depth + 1);
 523                         of_node_put(c);
 524                         if (ret != 0)
 525                                 return ret;
 526                 }
 527                 i++;
 528         } while (c);
 529
 530         /* Now check for cores */
 531         i = 0;
 532         do {
 533                 snprintf(name, sizeof(name), "core%d", i);
 534                 c = of_get_child_by_name(cluster, name);
 535                 if (c) {
 536                         has_cores = true;
 537
 538                         if (depth == 0) {
 539                                 pr_err("%pOF: cpu-map children should be clusters\n",
 540                                        c);
 541                                 of_node_put(c);
 542                                 return -EINVAL;
 543                         }
 544
 545                         if (leaf) {
 546                                 ret = parse_core(c, package_id, core_id++);
 547                         } else {
 548                                 pr_err("%pOF: Non-leaf cluster with core %s\n",
 549                                        cluster, name);
 550                                 ret = -EINVAL;
 551                         }
 552
 553                         of_node_put(c);
 554                         if (ret != 0)
 555                                 return ret;
 556                 }
 557                 i++;
 558         } while (c);
 559
 560         if (leaf && !has_cores)
 561                 pr_warn("%pOF: empty cluster\n", cluster);
 562
 563         if (leaf)
 564                 package_id++;
 565
 566         return 0;
 567 }
 568
 569 static int __init parse_dt_topology(void)
 570 {
 571         struct device_node *cn, *map;
 572         int ret = 0;
 573         int cpu;
 574
 575         cn = of_find_node_by_path("/cpus");
 576         if (!cn) {
 577                 pr_err("No CPU information found in DT\n");
 578                 return 0;
 579         }
 580
 581         /*
 582          * When topology is provided cpu-map is essentially a root
 583          * cluster with restricted subnodes.
 584          */
 585         map = of_get_child_by_name(cn, "cpu-map");
 586         if (!map)
 587                 goto out;
 588
 589         ret = parse_cluster(map, 0);
 590         if (ret != 0)
 591                 goto out_map;
 592
 593         topology_normalize_cpu_scale();
 594
 595         /*
 596          * Check that all cores are in the topology; the SMP code will
 597          * only mark cores described in the DT as possible.
 598          */
 599         for_each_possible_cpu(cpu)
 600                 if (cpu_topology[cpu].package_id == -1)
 601                         ret = -EINVAL;
 602
 603 out_map:
 604         of_node_put(map);
 605 out:
 606         of_node_put(cn);
 607         return ret;
 608 }
 609 #endif
 610
 611 /*
 612  * cpu topology table
 613  */
 614 struct cpu_topology cpu_topology[NR_CPUS];
 615 EXPORT_SYMBOL_GPL(cpu_topology);
 616
 617 const struct cpumask *cpu_coregroup_mask(int cpu)
 618 {
 619         const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));
 620
 621         /* Find the smaller of NUMA, core or LLC siblings */
 622         if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
 623                 /* not numa in package, lets use the package siblings */
 624                 core_mask = &cpu_topology[cpu].core_sibling;
 625         }
 626         if (cpu_topology[cpu].llc_id != -1) {
 627                 if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
 628                         core_mask = &cpu_topology[cpu].llc_sibling;
 629         }
 630
 631         return core_mask;
 632 }
 633
 634 const struct cpumask *cpu_clustergroup_mask(int cpu)
 635 {
 636         return &cpu_topology[cpu].cluster_sibling;
 637 }
 638
 639 void update_siblings_masks(unsigned int cpuid)
 640 {
 641         struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
 642         int cpu;
 643
 644         /* update core and thread sibling masks */
 645         for_each_online_cpu(cpu) {
 646                 cpu_topo = &cpu_topology[cpu];
 647
 648                 if (cpuid_topo->llc_id == cpu_topo->llc_id) {
 649                         cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
 650                         cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
 651                 }
 652
 653                 if (cpuid_topo->package_id != cpu_topo->package_id)
 654                         continue;
 655
 656                 if (cpuid_topo->cluster_id == cpu_topo->cluster_id &&
 657                     cpuid_topo->cluster_id != -1) {
 658                         cpumask_set_cpu(cpu, &cpuid_topo->cluster_sibling);
 659                         cpumask_set_cpu(cpuid, &cpu_topo->cluster_sibling);
 660                 }
 661
 662                 cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
 663                 cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
 664
 665                 if (cpuid_topo->core_id != cpu_topo->core_id)
 666                         continue;
 667
 668                 cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
 669                 cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
 670         }
 671 }
 672
 673 static void clear_cpu_topology(int cpu)
 674 {
 675         struct cpu_topology *cpu_topo = &cpu_topology[cpu];
 676
 677         cpumask_clear(&cpu_topo->llc_sibling);
 678         cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);
 679
 680         cpumask_clear(&cpu_topo->cluster_sibling);
 681         cpumask_set_cpu(cpu, &cpu_topo->cluster_sibling);
 682
 683         cpumask_clear(&cpu_topo->core_sibling);
 684         cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
 685         cpumask_clear(&cpu_topo->thread_sibling);
 686         cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
 687 }
 688
 689 void __init reset_cpu_topology(void)
 690 {
 691         unsigned int cpu;
 692
 693         for_each_possible_cpu(cpu) {
 694                 struct cpu_topology *cpu_topo = &cpu_topology[cpu];
 695
 696                 cpu_topo->thread_id = -1;
 697                 cpu_topo->core_id = -1;
 698                 cpu_topo->cluster_id = -1;
 699                 cpu_topo->package_id = -1;
 700                 cpu_topo->llc_id = -1;
 701
 702                 clear_cpu_topology(cpu);
 703         }
 704 }
 705
 706 void remove_cpu_topology(unsigned int cpu)
 707 {
 708         int sibling;
 709
 710         for_each_cpu(sibling, topology_core_cpumask(cpu))
 711                 cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
 712         for_each_cpu(sibling, topology_sibling_cpumask(cpu))
 713                 cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
 714         for_each_cpu(sibling, topology_cluster_cpumask(cpu))
 715                 cpumask_clear_cpu(cpu, topology_cluster_cpumask(sibling));
 716         for_each_cpu(sibling, topology_llc_cpumask(cpu))
 717                 cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));
 718
 719         clear_cpu_topology(cpu);
 720 }
 721
 722 __weak int __init parse_acpi_topology(void)
 723 {
 724         return 0;
 725 }
 726
 727 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
 728 void __init init_cpu_topology(void)
 729 {
 730         reset_cpu_topology();
 731
 732         /*
 733          * Discard anything that was parsed if we hit an error so we
 734          * don't use partial information.
 735          */
 736         if (parse_acpi_topology())
 737                 reset_cpu_topology();
 738         else if (of_have_populated_dt() && parse_dt_topology())
 739                 reset_cpu_topology();
 740 }
 741 #endif