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