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/sched.h> 22 #include <linux/smp.h> 23 24 DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE; 25 26 void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, 27 unsigned long max_freq) 28 { 29 unsigned long scale; 30 int i; 31 32 scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq; 33 34 for_each_cpu(i, cpus) 35 per_cpu(freq_scale, i) = scale; 36 } 37 38 DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE; 39 40 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity) 41 { 42 per_cpu(cpu_scale, cpu) = capacity; 43 } 44 45 static ssize_t cpu_capacity_show(struct device *dev, 46 struct device_attribute *attr, 47 char *buf) 48 { 49 struct cpu *cpu = container_of(dev, struct cpu, dev); 50 51 return sprintf(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id)); 52 } 53 54 static void update_topology_flags_workfn(struct work_struct *work); 55 static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn); 56 57 static DEVICE_ATTR_RO(cpu_capacity); 58 59 static int register_cpu_capacity_sysctl(void) 60 { 61 int i; 62 struct device *cpu; 63 64 for_each_possible_cpu(i) { 65 cpu = get_cpu_device(i); 66 if (!cpu) { 67 pr_err("%s: too early to get CPU%d device!\n", 68 __func__, i); 69 continue; 70 } 71 device_create_file(cpu, &dev_attr_cpu_capacity); 72 } 73 74 return 0; 75 } 76 subsys_initcall(register_cpu_capacity_sysctl); 77 78 static int update_topology; 79 80 int topology_update_cpu_topology(void) 81 { 82 return update_topology; 83 } 84 85 /* 86 * Updating the sched_domains can't be done directly from cpufreq callbacks 87 * due to locking, so queue the work for later. 88 */ 89 static void update_topology_flags_workfn(struct work_struct *work) 90 { 91 update_topology = 1; 92 rebuild_sched_domains(); 93 pr_debug("sched_domain hierarchy rebuilt, flags updated\n"); 94 update_topology = 0; 95 } 96 97 static u32 capacity_scale; 98 static u32 *raw_capacity; 99 100 static int free_raw_capacity(void) 101 { 102 kfree(raw_capacity); 103 raw_capacity = NULL; 104 105 return 0; 106 } 107 108 void topology_normalize_cpu_scale(void) 109 { 110 u64 capacity; 111 int cpu; 112 113 if (!raw_capacity) 114 return; 115 116 pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale); 117 for_each_possible_cpu(cpu) { 118 pr_debug("cpu_capacity: cpu=%d raw_capacity=%u\n", 119 cpu, raw_capacity[cpu]); 120 capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT) 121 / capacity_scale; 122 topology_set_cpu_scale(cpu, capacity); 123 pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n", 124 cpu, topology_get_cpu_scale(cpu)); 125 } 126 } 127 128 bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu) 129 { 130 static bool cap_parsing_failed; 131 int ret; 132 u32 cpu_capacity; 133 134 if (cap_parsing_failed) 135 return false; 136 137 ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz", 138 &cpu_capacity); 139 if (!ret) { 140 if (!raw_capacity) { 141 raw_capacity = kcalloc(num_possible_cpus(), 142 sizeof(*raw_capacity), 143 GFP_KERNEL); 144 if (!raw_capacity) { 145 cap_parsing_failed = true; 146 return false; 147 } 148 } 149 capacity_scale = max(cpu_capacity, capacity_scale); 150 raw_capacity[cpu] = cpu_capacity; 151 pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n", 152 cpu_node, raw_capacity[cpu]); 153 } else { 154 if (raw_capacity) { 155 pr_err("cpu_capacity: missing %pOF raw capacity\n", 156 cpu_node); 157 pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n"); 158 } 159 cap_parsing_failed = true; 160 free_raw_capacity(); 161 } 162 163 return !ret; 164 } 165 166 #ifdef CONFIG_CPU_FREQ 167 static cpumask_var_t cpus_to_visit; 168 static void parsing_done_workfn(struct work_struct *work); 169 static DECLARE_WORK(parsing_done_work, parsing_done_workfn); 170 171 static int 172 init_cpu_capacity_callback(struct notifier_block *nb, 173 unsigned long val, 174 void *data) 175 { 176 struct cpufreq_policy *policy = data; 177 int cpu; 178 179 if (!raw_capacity) 180 return 0; 181 182 if (val != CPUFREQ_CREATE_POLICY) 183 return 0; 184 185 pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n", 186 cpumask_pr_args(policy->related_cpus), 187 cpumask_pr_args(cpus_to_visit)); 188 189 cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus); 190 191 for_each_cpu(cpu, policy->related_cpus) { 192 raw_capacity[cpu] = topology_get_cpu_scale(cpu) * 193 policy->cpuinfo.max_freq / 1000UL; 194 capacity_scale = max(raw_capacity[cpu], capacity_scale); 195 } 196 197 if (cpumask_empty(cpus_to_visit)) { 198 topology_normalize_cpu_scale(); 199 schedule_work(&update_topology_flags_work); 200 free_raw_capacity(); 201 pr_debug("cpu_capacity: parsing done\n"); 202 schedule_work(&parsing_done_work); 203 } 204 205 return 0; 206 } 207 208 static struct notifier_block init_cpu_capacity_notifier = { 209 .notifier_call = init_cpu_capacity_callback, 210 }; 211 212 static int __init register_cpufreq_notifier(void) 213 { 214 int ret; 215 216 /* 217 * on ACPI-based systems we need to use the default cpu capacity 218 * until we have the necessary code to parse the cpu capacity, so 219 * skip registering cpufreq notifier. 220 */ 221 if (!acpi_disabled || !raw_capacity) 222 return -EINVAL; 223 224 if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) 225 return -ENOMEM; 226 227 cpumask_copy(cpus_to_visit, cpu_possible_mask); 228 229 ret = cpufreq_register_notifier(&init_cpu_capacity_notifier, 230 CPUFREQ_POLICY_NOTIFIER); 231 232 if (ret) 233 free_cpumask_var(cpus_to_visit); 234 235 return ret; 236 } 237 core_initcall(register_cpufreq_notifier); 238 239 static void parsing_done_workfn(struct work_struct *work) 240 { 241 cpufreq_unregister_notifier(&init_cpu_capacity_notifier, 242 CPUFREQ_POLICY_NOTIFIER); 243 free_cpumask_var(cpus_to_visit); 244 } 245 246 #else 247 core_initcall(free_raw_capacity); 248 #endif 249 250 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV) 251 static int __init get_cpu_for_node(struct device_node *node) 252 { 253 struct device_node *cpu_node; 254 int cpu; 255 256 cpu_node = of_parse_phandle(node, "cpu", 0); 257 if (!cpu_node) 258 return -1; 259 260 cpu = of_cpu_node_to_id(cpu_node); 261 if (cpu >= 0) 262 topology_parse_cpu_capacity(cpu_node, cpu); 263 else 264 pr_crit("Unable to find CPU node for %pOF\n", cpu_node); 265 266 of_node_put(cpu_node); 267 return cpu; 268 } 269 270 static int __init parse_core(struct device_node *core, int package_id, 271 int core_id) 272 { 273 char name[10]; 274 bool leaf = true; 275 int i = 0; 276 int cpu; 277 struct device_node *t; 278 279 do { 280 snprintf(name, sizeof(name), "thread%d", i); 281 t = of_get_child_by_name(core, name); 282 if (t) { 283 leaf = false; 284 cpu = get_cpu_for_node(t); 285 if (cpu >= 0) { 286 cpu_topology[cpu].package_id = package_id; 287 cpu_topology[cpu].core_id = core_id; 288 cpu_topology[cpu].thread_id = i; 289 } else { 290 pr_err("%pOF: Can't get CPU for thread\n", 291 t); 292 of_node_put(t); 293 return -EINVAL; 294 } 295 of_node_put(t); 296 } 297 i++; 298 } while (t); 299 300 cpu = get_cpu_for_node(core); 301 if (cpu >= 0) { 302 if (!leaf) { 303 pr_err("%pOF: Core has both threads and CPU\n", 304 core); 305 return -EINVAL; 306 } 307 308 cpu_topology[cpu].package_id = package_id; 309 cpu_topology[cpu].core_id = core_id; 310 } else if (leaf) { 311 pr_err("%pOF: Can't get CPU for leaf core\n", core); 312 return -EINVAL; 313 } 314 315 return 0; 316 } 317 318 static int __init parse_cluster(struct device_node *cluster, int depth) 319 { 320 char name[10]; 321 bool leaf = true; 322 bool has_cores = false; 323 struct device_node *c; 324 static int package_id __initdata; 325 int core_id = 0; 326 int i, ret; 327 328 /* 329 * First check for child clusters; we currently ignore any 330 * information about the nesting of clusters and present the 331 * scheduler with a flat list of them. 332 */ 333 i = 0; 334 do { 335 snprintf(name, sizeof(name), "cluster%d", i); 336 c = of_get_child_by_name(cluster, name); 337 if (c) { 338 leaf = false; 339 ret = parse_cluster(c, depth + 1); 340 of_node_put(c); 341 if (ret != 0) 342 return ret; 343 } 344 i++; 345 } while (c); 346 347 /* Now check for cores */ 348 i = 0; 349 do { 350 snprintf(name, sizeof(name), "core%d", i); 351 c = of_get_child_by_name(cluster, name); 352 if (c) { 353 has_cores = true; 354 355 if (depth == 0) { 356 pr_err("%pOF: cpu-map children should be clusters\n", 357 c); 358 of_node_put(c); 359 return -EINVAL; 360 } 361 362 if (leaf) { 363 ret = parse_core(c, package_id, core_id++); 364 } else { 365 pr_err("%pOF: Non-leaf cluster with core %s\n", 366 cluster, name); 367 ret = -EINVAL; 368 } 369 370 of_node_put(c); 371 if (ret != 0) 372 return ret; 373 } 374 i++; 375 } while (c); 376 377 if (leaf && !has_cores) 378 pr_warn("%pOF: empty cluster\n", cluster); 379 380 if (leaf) 381 package_id++; 382 383 return 0; 384 } 385 386 static int __init parse_dt_topology(void) 387 { 388 struct device_node *cn, *map; 389 int ret = 0; 390 int cpu; 391 392 cn = of_find_node_by_path("/cpus"); 393 if (!cn) { 394 pr_err("No CPU information found in DT\n"); 395 return 0; 396 } 397 398 /* 399 * When topology is provided cpu-map is essentially a root 400 * cluster with restricted subnodes. 401 */ 402 map = of_get_child_by_name(cn, "cpu-map"); 403 if (!map) 404 goto out; 405 406 ret = parse_cluster(map, 0); 407 if (ret != 0) 408 goto out_map; 409 410 topology_normalize_cpu_scale(); 411 412 /* 413 * Check that all cores are in the topology; the SMP code will 414 * only mark cores described in the DT as possible. 415 */ 416 for_each_possible_cpu(cpu) 417 if (cpu_topology[cpu].package_id == -1) 418 ret = -EINVAL; 419 420 out_map: 421 of_node_put(map); 422 out: 423 of_node_put(cn); 424 return ret; 425 } 426 #endif 427 428 /* 429 * cpu topology table 430 */ 431 struct cpu_topology cpu_topology[NR_CPUS]; 432 EXPORT_SYMBOL_GPL(cpu_topology); 433 434 const struct cpumask *cpu_coregroup_mask(int cpu) 435 { 436 const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu)); 437 438 /* Find the smaller of NUMA, core or LLC siblings */ 439 if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) { 440 /* not numa in package, lets use the package siblings */ 441 core_mask = &cpu_topology[cpu].core_sibling; 442 } 443 if (cpu_topology[cpu].llc_id != -1) { 444 if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask)) 445 core_mask = &cpu_topology[cpu].llc_sibling; 446 } 447 448 return core_mask; 449 } 450 451 void update_siblings_masks(unsigned int cpuid) 452 { 453 struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid]; 454 int cpu; 455 456 /* update core and thread sibling masks */ 457 for_each_online_cpu(cpu) { 458 cpu_topo = &cpu_topology[cpu]; 459 460 if (cpuid_topo->llc_id == cpu_topo->llc_id) { 461 cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling); 462 cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling); 463 } 464 465 if (cpuid_topo->package_id != cpu_topo->package_id) 466 continue; 467 468 cpumask_set_cpu(cpuid, &cpu_topo->core_sibling); 469 cpumask_set_cpu(cpu, &cpuid_topo->core_sibling); 470 471 if (cpuid_topo->core_id != cpu_topo->core_id) 472 continue; 473 474 cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling); 475 cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling); 476 } 477 } 478 479 static void clear_cpu_topology(int cpu) 480 { 481 struct cpu_topology *cpu_topo = &cpu_topology[cpu]; 482 483 cpumask_clear(&cpu_topo->llc_sibling); 484 cpumask_set_cpu(cpu, &cpu_topo->llc_sibling); 485 486 cpumask_clear(&cpu_topo->core_sibling); 487 cpumask_set_cpu(cpu, &cpu_topo->core_sibling); 488 cpumask_clear(&cpu_topo->thread_sibling); 489 cpumask_set_cpu(cpu, &cpu_topo->thread_sibling); 490 } 491 492 void __init reset_cpu_topology(void) 493 { 494 unsigned int cpu; 495 496 for_each_possible_cpu(cpu) { 497 struct cpu_topology *cpu_topo = &cpu_topology[cpu]; 498 499 cpu_topo->thread_id = -1; 500 cpu_topo->core_id = -1; 501 cpu_topo->package_id = -1; 502 cpu_topo->llc_id = -1; 503 504 clear_cpu_topology(cpu); 505 } 506 } 507 508 void remove_cpu_topology(unsigned int cpu) 509 { 510 int sibling; 511 512 for_each_cpu(sibling, topology_core_cpumask(cpu)) 513 cpumask_clear_cpu(cpu, topology_core_cpumask(sibling)); 514 for_each_cpu(sibling, topology_sibling_cpumask(cpu)) 515 cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling)); 516 for_each_cpu(sibling, topology_llc_cpumask(cpu)) 517 cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling)); 518 519 clear_cpu_topology(cpu); 520 } 521 522 __weak int __init parse_acpi_topology(void) 523 { 524 return 0; 525 } 526 527 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV) 528 void __init init_cpu_topology(void) 529 { 530 reset_cpu_topology(); 531 532 /* 533 * Discard anything that was parsed if we hit an error so we 534 * don't use partial information. 535 */ 536 if (parse_acpi_topology()) 537 reset_cpu_topology(); 538 else if (of_have_populated_dt() && parse_dt_topology()) 539 reset_cpu_topology(); 540 } 541 #endif 542