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 /* 252 * This function returns the logic cpu number of the node. 253 * There are basically three kinds of return values: 254 * (1) logic cpu number which is > 0. 255 * (2) -ENODEV when the device tree(DT) node is valid and found in the DT but 256 * there is no possible logical CPU in the kernel to match. This happens 257 * when CONFIG_NR_CPUS is configure to be smaller than the number of 258 * CPU nodes in DT. We need to just ignore this case. 259 * (3) -1 if the node does not exist in the device tree 260 */ 261 static int __init get_cpu_for_node(struct device_node *node) 262 { 263 struct device_node *cpu_node; 264 int cpu; 265 266 cpu_node = of_parse_phandle(node, "cpu", 0); 267 if (!cpu_node) 268 return -1; 269 270 cpu = of_cpu_node_to_id(cpu_node); 271 if (cpu >= 0) 272 topology_parse_cpu_capacity(cpu_node, cpu); 273 else 274 pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n", 275 cpu_node, cpumask_pr_args(cpu_possible_mask)); 276 277 of_node_put(cpu_node); 278 return cpu; 279 } 280 281 static int __init parse_core(struct device_node *core, int package_id, 282 int core_id) 283 { 284 char name[10]; 285 bool leaf = true; 286 int i = 0; 287 int cpu; 288 struct device_node *t; 289 290 do { 291 snprintf(name, sizeof(name), "thread%d", i); 292 t = of_get_child_by_name(core, name); 293 if (t) { 294 leaf = false; 295 cpu = get_cpu_for_node(t); 296 if (cpu >= 0) { 297 cpu_topology[cpu].package_id = package_id; 298 cpu_topology[cpu].core_id = core_id; 299 cpu_topology[cpu].thread_id = i; 300 } else if (cpu != -ENODEV) { 301 pr_err("%pOF: Can't get CPU for thread\n", t); 302 of_node_put(t); 303 return -EINVAL; 304 } 305 of_node_put(t); 306 } 307 i++; 308 } while (t); 309 310 cpu = get_cpu_for_node(core); 311 if (cpu >= 0) { 312 if (!leaf) { 313 pr_err("%pOF: Core has both threads and CPU\n", 314 core); 315 return -EINVAL; 316 } 317 318 cpu_topology[cpu].package_id = package_id; 319 cpu_topology[cpu].core_id = core_id; 320 } else if (leaf && cpu != -ENODEV) { 321 pr_err("%pOF: Can't get CPU for leaf core\n", core); 322 return -EINVAL; 323 } 324 325 return 0; 326 } 327 328 static int __init parse_cluster(struct device_node *cluster, int depth) 329 { 330 char name[10]; 331 bool leaf = true; 332 bool has_cores = false; 333 struct device_node *c; 334 static int package_id __initdata; 335 int core_id = 0; 336 int i, ret; 337 338 /* 339 * First check for child clusters; we currently ignore any 340 * information about the nesting of clusters and present the 341 * scheduler with a flat list of them. 342 */ 343 i = 0; 344 do { 345 snprintf(name, sizeof(name), "cluster%d", i); 346 c = of_get_child_by_name(cluster, name); 347 if (c) { 348 leaf = false; 349 ret = parse_cluster(c, depth + 1); 350 of_node_put(c); 351 if (ret != 0) 352 return ret; 353 } 354 i++; 355 } while (c); 356 357 /* Now check for cores */ 358 i = 0; 359 do { 360 snprintf(name, sizeof(name), "core%d", i); 361 c = of_get_child_by_name(cluster, name); 362 if (c) { 363 has_cores = true; 364 365 if (depth == 0) { 366 pr_err("%pOF: cpu-map children should be clusters\n", 367 c); 368 of_node_put(c); 369 return -EINVAL; 370 } 371 372 if (leaf) { 373 ret = parse_core(c, package_id, core_id++); 374 } else { 375 pr_err("%pOF: Non-leaf cluster with core %s\n", 376 cluster, name); 377 ret = -EINVAL; 378 } 379 380 of_node_put(c); 381 if (ret != 0) 382 return ret; 383 } 384 i++; 385 } while (c); 386 387 if (leaf && !has_cores) 388 pr_warn("%pOF: empty cluster\n", cluster); 389 390 if (leaf) 391 package_id++; 392 393 return 0; 394 } 395 396 static int __init parse_dt_topology(void) 397 { 398 struct device_node *cn, *map; 399 int ret = 0; 400 int cpu; 401 402 cn = of_find_node_by_path("/cpus"); 403 if (!cn) { 404 pr_err("No CPU information found in DT\n"); 405 return 0; 406 } 407 408 /* 409 * When topology is provided cpu-map is essentially a root 410 * cluster with restricted subnodes. 411 */ 412 map = of_get_child_by_name(cn, "cpu-map"); 413 if (!map) 414 goto out; 415 416 ret = parse_cluster(map, 0); 417 if (ret != 0) 418 goto out_map; 419 420 topology_normalize_cpu_scale(); 421 422 /* 423 * Check that all cores are in the topology; the SMP code will 424 * only mark cores described in the DT as possible. 425 */ 426 for_each_possible_cpu(cpu) 427 if (cpu_topology[cpu].package_id == -1) 428 ret = -EINVAL; 429 430 out_map: 431 of_node_put(map); 432 out: 433 of_node_put(cn); 434 return ret; 435 } 436 #endif 437 438 /* 439 * cpu topology table 440 */ 441 struct cpu_topology cpu_topology[NR_CPUS]; 442 EXPORT_SYMBOL_GPL(cpu_topology); 443 444 const struct cpumask *cpu_coregroup_mask(int cpu) 445 { 446 const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu)); 447 448 /* Find the smaller of NUMA, core or LLC siblings */ 449 if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) { 450 /* not numa in package, lets use the package siblings */ 451 core_mask = &cpu_topology[cpu].core_sibling; 452 } 453 if (cpu_topology[cpu].llc_id != -1) { 454 if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask)) 455 core_mask = &cpu_topology[cpu].llc_sibling; 456 } 457 458 return core_mask; 459 } 460 461 void update_siblings_masks(unsigned int cpuid) 462 { 463 struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid]; 464 int cpu; 465 466 /* update core and thread sibling masks */ 467 for_each_online_cpu(cpu) { 468 cpu_topo = &cpu_topology[cpu]; 469 470 if (cpuid_topo->llc_id == cpu_topo->llc_id) { 471 cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling); 472 cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling); 473 } 474 475 if (cpuid_topo->package_id != cpu_topo->package_id) 476 continue; 477 478 cpumask_set_cpu(cpuid, &cpu_topo->core_sibling); 479 cpumask_set_cpu(cpu, &cpuid_topo->core_sibling); 480 481 if (cpuid_topo->core_id != cpu_topo->core_id) 482 continue; 483 484 cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling); 485 cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling); 486 } 487 } 488 489 static void clear_cpu_topology(int cpu) 490 { 491 struct cpu_topology *cpu_topo = &cpu_topology[cpu]; 492 493 cpumask_clear(&cpu_topo->llc_sibling); 494 cpumask_set_cpu(cpu, &cpu_topo->llc_sibling); 495 496 cpumask_clear(&cpu_topo->core_sibling); 497 cpumask_set_cpu(cpu, &cpu_topo->core_sibling); 498 cpumask_clear(&cpu_topo->thread_sibling); 499 cpumask_set_cpu(cpu, &cpu_topo->thread_sibling); 500 } 501 502 void __init reset_cpu_topology(void) 503 { 504 unsigned int cpu; 505 506 for_each_possible_cpu(cpu) { 507 struct cpu_topology *cpu_topo = &cpu_topology[cpu]; 508 509 cpu_topo->thread_id = -1; 510 cpu_topo->core_id = -1; 511 cpu_topo->package_id = -1; 512 cpu_topo->llc_id = -1; 513 514 clear_cpu_topology(cpu); 515 } 516 } 517 518 void remove_cpu_topology(unsigned int cpu) 519 { 520 int sibling; 521 522 for_each_cpu(sibling, topology_core_cpumask(cpu)) 523 cpumask_clear_cpu(cpu, topology_core_cpumask(sibling)); 524 for_each_cpu(sibling, topology_sibling_cpumask(cpu)) 525 cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling)); 526 for_each_cpu(sibling, topology_llc_cpumask(cpu)) 527 cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling)); 528 529 clear_cpu_topology(cpu); 530 } 531 532 __weak int __init parse_acpi_topology(void) 533 { 534 return 0; 535 } 536 537 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV) 538 void __init init_cpu_topology(void) 539 { 540 reset_cpu_topology(); 541 542 /* 543 * Discard anything that was parsed if we hit an error so we 544 * don't use partial information. 545 */ 546 if (parse_acpi_topology()) 547 reset_cpu_topology(); 548 else if (of_have_populated_dt() && parse_dt_topology()) 549 reset_cpu_topology(); 550 } 551 #endif 552