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6ee97d35 1// SPDX-License-Identifier: GPL-2.0
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2/*
3 * Arch specific cpu topology information
4 *
5 * Copyright (C) 2016, ARM Ltd.
6 * Written by: Juri Lelli, ARM Ltd.
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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>
bb1fbdd3 17#include <linux/cpuset.h>
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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>
2ef7a295 23
0e27c567 24DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE;
2ef7a295 25
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26void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
27 unsigned long max_freq)
2ef7a295 28{
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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;
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36}
37
8216f588 38DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
2ef7a295 39
4ca4f26a 40void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
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41{
42 per_cpu(cpu_scale, cpu) = capacity;
43}
44
45static 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
8ec59c0f 51 return sprintf(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
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52}
53
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54static void update_topology_flags_workfn(struct work_struct *work);
55static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
56
5d777b18 57static DEVICE_ATTR_RO(cpu_capacity);
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58
59static 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}
76subsys_initcall(register_cpu_capacity_sysctl);
77
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78static int update_topology;
79
80int 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 */
89static 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
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97static u32 capacity_scale;
98static u32 *raw_capacity;
62de1161 99
82d8ba71 100static int free_raw_capacity(void)
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101{
102 kfree(raw_capacity);
103 raw_capacity = NULL;
104
105 return 0;
106}
2ef7a295 107
4ca4f26a 108void topology_normalize_cpu_scale(void)
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109{
110 u64 capacity;
111 int cpu;
112
62de1161 113 if (!raw_capacity)
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114 return;
115
116 pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
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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;
4ca4f26a 122 topology_set_cpu_scale(cpu, capacity);
2ef7a295 123 pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
8ec59c0f 124 cpu, topology_get_cpu_scale(cpu));
2ef7a295 125 }
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126}
127
805df296 128bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
2ef7a295 129{
62de1161 130 static bool cap_parsing_failed;
805df296 131 int ret;
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132 u32 cpu_capacity;
133
134 if (cap_parsing_failed)
805df296 135 return false;
2ef7a295 136
3eeba1a2 137 ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
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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) {
2ef7a295 145 cap_parsing_failed = true;
805df296 146 return false;
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147 }
148 }
149 capacity_scale = max(cpu_capacity, capacity_scale);
150 raw_capacity[cpu] = cpu_capacity;
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151 pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
152 cpu_node, raw_capacity[cpu]);
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153 } else {
154 if (raw_capacity) {
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155 pr_err("cpu_capacity: missing %pOF raw capacity\n",
156 cpu_node);
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157 pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
158 }
159 cap_parsing_failed = true;
62de1161 160 free_raw_capacity();
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161 }
162
163 return !ret;
164}
165
166#ifdef CONFIG_CPU_FREQ
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167static cpumask_var_t cpus_to_visit;
168static void parsing_done_workfn(struct work_struct *work);
169static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
2ef7a295 170
9de9a449 171static int
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172init_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
d8bcf4db 179 if (!raw_capacity)
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180 return 0;
181
40f0fc2a 182 if (val != CPUFREQ_CREATE_POLICY)
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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) {
8ec59c0f 192 raw_capacity[cpu] = topology_get_cpu_scale(cpu) *
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193 policy->cpuinfo.max_freq / 1000UL;
194 capacity_scale = max(raw_capacity[cpu], capacity_scale);
2ef7a295 195 }
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196
197 if (cpumask_empty(cpus_to_visit)) {
198 topology_normalize_cpu_scale();
bb1fbdd3 199 schedule_work(&update_topology_flags_work);
62de1161 200 free_raw_capacity();
93a57081 201 pr_debug("cpu_capacity: parsing done\n");
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202 schedule_work(&parsing_done_work);
203 }
204
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205 return 0;
206}
207
9de9a449 208static struct notifier_block init_cpu_capacity_notifier = {
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209 .notifier_call = init_cpu_capacity_callback,
210};
211
212static int __init register_cpufreq_notifier(void)
213{
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214 int ret;
215
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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 */
c105aa31 221 if (!acpi_disabled || !raw_capacity)
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222 return -EINVAL;
223
0fd33116 224 if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL))
2ef7a295 225 return -ENOMEM;
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226
227 cpumask_copy(cpus_to_visit, cpu_possible_mask);
228
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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;
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236}
237core_initcall(register_cpufreq_notifier);
238
9de9a449 239static void parsing_done_workfn(struct work_struct *work)
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240{
241 cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
242 CPUFREQ_POLICY_NOTIFIER);
5408211a 243 free_cpumask_var(cpus_to_visit);
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244}
245
246#else
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247core_initcall(free_raw_capacity);
248#endif
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249
250#if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
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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 */
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261static 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
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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));
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276
277 of_node_put(cpu_node);
278 return cpu;
279}
280
281static 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;
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300 } else if (cpu != -ENODEV) {
301 pr_err("%pOF: Can't get CPU for thread\n", t);
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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;
f3c19481 320 } else if (leaf && cpu != -ENODEV) {
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321 pr_err("%pOF: Can't get CPU for leaf core\n", core);
322 return -EINVAL;
323 }
324
325 return 0;
326}
327
328static 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
396static 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
430out_map:
431 of_node_put(map);
432out:
433 of_node_put(cn);
434 return ret;
435}
ca74b316 436#endif
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437
438/*
439 * cpu topology table
440 */
441struct cpu_topology cpu_topology[NR_CPUS];
442EXPORT_SYMBOL_GPL(cpu_topology);
443
444const 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
461void 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
489static 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
ca74b316 502void __init reset_cpu_topology(void)
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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
518void 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
ca74b316 537#if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
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538void __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