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