summaryrefslogtreecommitdiff
path: root/drivers/base/arch_topology.c
blob: 75fcb75d551557efac69717b43046bf271a4dec4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
// SPDX-License-Identifier: GPL-2.0
/*
 * Arch specific cpu topology information
 *
 * Copyright (C) 2016, ARM Ltd.
 * Written by: Juri Lelli, ARM Ltd.
 */

#include <linux/acpi.h>
#include <linux/cacheinfo.h>
#include <linux/cleanup.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/sched/topology.h>
#include <linux/cpuset.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/rcupdate.h>
#include <linux/sched.h>
#include <linux/units.h>

#define CREATE_TRACE_POINTS
#include <trace/events/hw_pressure.h>

static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data);
static struct cpumask scale_freq_counters_mask;
static bool scale_freq_invariant;
DEFINE_PER_CPU(unsigned long, capacity_freq_ref) = 1;
EXPORT_PER_CPU_SYMBOL_GPL(capacity_freq_ref);

static bool supports_scale_freq_counters(const struct cpumask *cpus)
{
	return cpumask_subset(cpus, &scale_freq_counters_mask);
}

bool topology_scale_freq_invariant(void)
{
	return cpufreq_supports_freq_invariance() ||
	       supports_scale_freq_counters(cpu_online_mask);
}

static void update_scale_freq_invariant(bool status)
{
	if (scale_freq_invariant == status)
		return;

	/*
	 * Task scheduler behavior depends on frequency invariance support,
	 * either cpufreq or counter driven. If the support status changes as
	 * a result of counter initialisation and use, retrigger the build of
	 * scheduling domains to ensure the information is propagated properly.
	 */
	if (topology_scale_freq_invariant() == status) {
		scale_freq_invariant = status;
		rebuild_sched_domains_energy();
	}
}

void topology_set_scale_freq_source(struct scale_freq_data *data,
				    const struct cpumask *cpus)
{
	struct scale_freq_data *sfd;
	int cpu;

	/*
	 * Avoid calling rebuild_sched_domains() unnecessarily if FIE is
	 * supported by cpufreq.
	 */
	if (cpumask_empty(&scale_freq_counters_mask))
		scale_freq_invariant = topology_scale_freq_invariant();

	rcu_read_lock();

	for_each_cpu(cpu, cpus) {
		sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));

		/* Use ARCH provided counters whenever possible */
		if (!sfd || sfd->source != SCALE_FREQ_SOURCE_ARCH) {
			rcu_assign_pointer(per_cpu(sft_data, cpu), data);
			cpumask_set_cpu(cpu, &scale_freq_counters_mask);
		}
	}

	rcu_read_unlock();

	update_scale_freq_invariant(true);
}
EXPORT_SYMBOL_GPL(topology_set_scale_freq_source);

void topology_clear_scale_freq_source(enum scale_freq_source source,
				      const struct cpumask *cpus)
{
	struct scale_freq_data *sfd;
	int cpu;

	rcu_read_lock();

	for_each_cpu(cpu, cpus) {
		sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));

		if (sfd && sfd->source == source) {
			rcu_assign_pointer(per_cpu(sft_data, cpu), NULL);
			cpumask_clear_cpu(cpu, &scale_freq_counters_mask);
		}
	}

	rcu_read_unlock();

	/*
	 * Make sure all references to previous sft_data are dropped to avoid
	 * use-after-free races.
	 */
	synchronize_rcu();

	update_scale_freq_invariant(false);
}
EXPORT_SYMBOL_GPL(topology_clear_scale_freq_source);

void topology_scale_freq_tick(void)
{
	struct scale_freq_data *sfd = rcu_dereference_sched(*this_cpu_ptr(&sft_data));

	if (sfd)
		sfd->set_freq_scale();
}

DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
EXPORT_PER_CPU_SYMBOL_GPL(arch_freq_scale);

void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq,
			     unsigned long max_freq)
{
	unsigned long scale;
	int i;

	if (WARN_ON_ONCE(!cur_freq || !max_freq))
		return;

	/*
	 * If the use of counters for FIE is enabled, just return as we don't
	 * want to update the scale factor with information from CPUFREQ.
	 * Instead the scale factor will be updated from arch_scale_freq_tick.
	 */
	if (supports_scale_freq_counters(cpus))
		return;

	scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;

	for_each_cpu(i, cpus)
		per_cpu(arch_freq_scale, i) = scale;
}

DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);

void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
{
	per_cpu(cpu_scale, cpu) = capacity;
}

DEFINE_PER_CPU(unsigned long, hw_pressure);

/**
 * topology_update_hw_pressure() - Update HW pressure for CPUs
 * @cpus        : The related CPUs for which capacity has been reduced
 * @capped_freq : The maximum allowed frequency that CPUs can run at
 *
 * Update the value of HW pressure for all @cpus in the mask. The
 * cpumask should include all (online+offline) affected CPUs, to avoid
 * operating on stale data when hot-plug is used for some CPUs. The
 * @capped_freq reflects the currently allowed max CPUs frequency due to
 * HW capping. It might be also a boost frequency value, which is bigger
 * than the internal 'capacity_freq_ref' max frequency. In such case the
 * pressure value should simply be removed, since this is an indication that
 * there is no HW throttling. The @capped_freq must be provided in kHz.
 */
void topology_update_hw_pressure(const struct cpumask *cpus,
				      unsigned long capped_freq)
{
	unsigned long max_capacity, capacity, pressure;
	u32 max_freq;
	int cpu;

	cpu = cpumask_first(cpus);
	max_capacity = arch_scale_cpu_capacity(cpu);
	max_freq = arch_scale_freq_ref(cpu);

	/*
	 * Handle properly the boost frequencies, which should simply clean
	 * the HW pressure value.
	 */
	if (max_freq <= capped_freq)
		capacity = max_capacity;
	else
		capacity = mult_frac(max_capacity, capped_freq, max_freq);

	pressure = max_capacity - capacity;

	trace_hw_pressure_update(cpu, pressure);

	for_each_cpu(cpu, cpus)
		WRITE_ONCE(per_cpu(hw_pressure, cpu), pressure);
}
EXPORT_SYMBOL_GPL(topology_update_hw_pressure);

static ssize_t cpu_capacity_show(struct device *dev,
				 struct device_attribute *attr,
				 char *buf)
{
	struct cpu *cpu = container_of(dev, struct cpu, dev);

	return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
}

static void update_topology_flags_workfn(struct work_struct *work);
static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);

static DEVICE_ATTR_RO(cpu_capacity);

static int cpu_capacity_sysctl_add(unsigned int cpu)
{
	struct device *cpu_dev = get_cpu_device(cpu);

	if (!cpu_dev)
		return -ENOENT;

	device_create_file(cpu_dev, &dev_attr_cpu_capacity);

	return 0;
}

static int cpu_capacity_sysctl_remove(unsigned int cpu)
{
	struct device *cpu_dev = get_cpu_device(cpu);

	if (!cpu_dev)
		return -ENOENT;

	device_remove_file(cpu_dev, &dev_attr_cpu_capacity);

	return 0;
}

static int register_cpu_capacity_sysctl(void)
{
	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "topology/cpu-capacity",
			  cpu_capacity_sysctl_add, cpu_capacity_sysctl_remove);

	return 0;
}
subsys_initcall(register_cpu_capacity_sysctl);

static int update_topology;

int topology_update_cpu_topology(void)
{
	return update_topology;
}

/*
 * Updating the sched_domains can't be done directly from cpufreq callbacks
 * due to locking, so queue the work for later.
 */
static void update_topology_flags_workfn(struct work_struct *work)
{
	update_topology = 1;
	rebuild_sched_domains();
	pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
	update_topology = 0;
}

static u32 *raw_capacity;

static int free_raw_capacity(void)
{
	kfree(raw_capacity);
	raw_capacity = NULL;

	return 0;
}

void topology_normalize_cpu_scale(void)
{
	u64 capacity;
	u64 capacity_scale;
	int cpu;

	if (!raw_capacity)
		return;

	capacity_scale = 1;
	for_each_possible_cpu(cpu) {
		capacity = raw_capacity[cpu] * per_cpu(capacity_freq_ref, cpu);
		capacity_scale = max(capacity, capacity_scale);
	}

	pr_debug("cpu_capacity: capacity_scale=%llu\n", capacity_scale);
	for_each_possible_cpu(cpu) {
		capacity = raw_capacity[cpu] * per_cpu(capacity_freq_ref, cpu);
		capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT,
			capacity_scale);
		topology_set_cpu_scale(cpu, capacity);
		pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
			cpu, topology_get_cpu_scale(cpu));
	}
}

bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
{
	struct clk *cpu_clk;
	static bool cap_parsing_failed;
	int ret;
	u32 cpu_capacity;

	if (cap_parsing_failed)
		return false;

	ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
				   &cpu_capacity);
	if (!ret) {
		if (!raw_capacity) {
			raw_capacity = kcalloc(num_possible_cpus(),
					       sizeof(*raw_capacity),
					       GFP_KERNEL);
			if (!raw_capacity) {
				cap_parsing_failed = true;
				return false;
			}
		}
		raw_capacity[cpu] = cpu_capacity;
		pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
			cpu_node, raw_capacity[cpu]);

		/*
		 * Update capacity_freq_ref for calculating early boot CPU capacities.
		 * For non-clk CPU DVFS mechanism, there's no way to get the
		 * frequency value now, assuming they are running at the same
		 * frequency (by keeping the initial capacity_freq_ref value).
		 */
		cpu_clk = of_clk_get(cpu_node, 0);
		if (!PTR_ERR_OR_ZERO(cpu_clk)) {
			per_cpu(capacity_freq_ref, cpu) =
				clk_get_rate(cpu_clk) / HZ_PER_KHZ;
			clk_put(cpu_clk);
		}
	} else {
		if (raw_capacity) {
			pr_err("cpu_capacity: missing %pOF raw capacity\n",
				cpu_node);
			pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
		}
		cap_parsing_failed = true;
		free_raw_capacity();
	}

	return !ret;
}

void __weak freq_inv_set_max_ratio(int cpu, u64 max_rate)
{
}

#ifdef CONFIG_ACPI_CPPC_LIB
#include <acpi/cppc_acpi.h>

void topology_init_cpu_capacity_cppc(void)
{
	u64 capacity, capacity_scale = 0;
	struct cppc_perf_caps perf_caps;
	int cpu;

	if (likely(!acpi_cpc_valid()))
		return;

	raw_capacity = kcalloc(num_possible_cpus(), sizeof(*raw_capacity),
			       GFP_KERNEL);
	if (!raw_capacity)
		return;

	for_each_possible_cpu(cpu) {
		if (!cppc_get_perf_caps(cpu, &perf_caps) &&
		    (perf_caps.highest_perf >= perf_caps.nominal_perf) &&
		    (perf_caps.highest_perf >= perf_caps.lowest_perf)) {
			raw_capacity[cpu] = perf_caps.highest_perf;
			capacity_scale = max_t(u64, capacity_scale, raw_capacity[cpu]);

			per_cpu(capacity_freq_ref, cpu) = cppc_perf_to_khz(&perf_caps, raw_capacity[cpu]);

			pr_debug("cpu_capacity: CPU%d cpu_capacity=%u (raw).\n",
				 cpu, raw_capacity[cpu]);
			continue;
		}

		pr_err("cpu_capacity: CPU%d missing/invalid highest performance.\n", cpu);
		pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
		goto exit;
	}

	for_each_possible_cpu(cpu) {
		freq_inv_set_max_ratio(cpu,
				       per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ);

		capacity = raw_capacity[cpu];
		capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT,
				     capacity_scale);
		topology_set_cpu_scale(cpu, capacity);
		pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
			cpu, topology_get_cpu_scale(cpu));
	}

	schedule_work(&update_topology_flags_work);
	pr_debug("cpu_capacity: cpu_capacity initialization done\n");

exit:
	free_raw_capacity();
}
#endif

#ifdef CONFIG_CPU_FREQ
static cpumask_var_t cpus_to_visit;
static void parsing_done_workfn(struct work_struct *work);
static DECLARE_WORK(parsing_done_work, parsing_done_workfn);

static int
init_cpu_capacity_callback(struct notifier_block *nb,
			   unsigned long val,
			   void *data)
{
	struct cpufreq_policy *policy = data;
	int cpu;

	if (val != CPUFREQ_CREATE_POLICY)
		return 0;

	pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
		 cpumask_pr_args(policy->related_cpus),
		 cpumask_pr_args(cpus_to_visit));

	cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);

	for_each_cpu(cpu, policy->related_cpus) {
		per_cpu(capacity_freq_ref, cpu) = policy->cpuinfo.max_freq;
		freq_inv_set_max_ratio(cpu,
				       per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ);
	}

	if (cpumask_empty(cpus_to_visit)) {
		if (raw_capacity) {
			topology_normalize_cpu_scale();
			schedule_work(&update_topology_flags_work);
			free_raw_capacity();
		}
		pr_debug("cpu_capacity: parsing done\n");
		schedule_work(&parsing_done_work);
	}

	return 0;
}

static struct notifier_block init_cpu_capacity_notifier = {
	.notifier_call = init_cpu_capacity_callback,
};

static int __init register_cpufreq_notifier(void)
{
	int ret;

	/*
	 * On ACPI-based systems skip registering cpufreq notifier as cpufreq
	 * information is not needed for cpu capacity initialization.
	 */
	if (!acpi_disabled)
		return -EINVAL;

	if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL))
		return -ENOMEM;

	cpumask_copy(cpus_to_visit, cpu_possible_mask);

	ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
					CPUFREQ_POLICY_NOTIFIER);

	if (ret)
		free_cpumask_var(cpus_to_visit);

	return ret;
}
core_initcall(register_cpufreq_notifier);

static void parsing_done_workfn(struct work_struct *work)
{
	cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
					 CPUFREQ_POLICY_NOTIFIER);
	free_cpumask_var(cpus_to_visit);
}

#else
core_initcall(free_raw_capacity);
#endif

#if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
/*
 * This function returns the logic cpu number of the node.
 * There are basically three kinds of return values:
 * (1) logic cpu number which is > 0.
 * (2) -ENODEV when the device tree(DT) node is valid and found in the DT but
 * there is no possible logical CPU in the kernel to match. This happens
 * when CONFIG_NR_CPUS is configure to be smaller than the number of
 * CPU nodes in DT. We need to just ignore this case.
 * (3) -1 if the node does not exist in the device tree
 */
static int __init get_cpu_for_node(struct device_node *node)
{
	int cpu;
	struct device_node *cpu_node __free(device_node) =
		of_parse_phandle(node, "cpu", 0);

	if (!cpu_node)
		return -1;

	cpu = of_cpu_node_to_id(cpu_node);
	if (cpu >= 0)
		topology_parse_cpu_capacity(cpu_node, cpu);
	else
		pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n",
			cpu_node, cpumask_pr_args(cpu_possible_mask));

	return cpu;
}

static int __init parse_core(struct device_node *core, int package_id,
			     int cluster_id, int core_id)
{
	char name[20];
	bool leaf = true;
	int i = 0;
	int cpu;

	do {
		snprintf(name, sizeof(name), "thread%d", i);
		struct device_node *t __free(device_node) =
			of_get_child_by_name(core, name);

		if (!t)
			break;

		leaf = false;
		cpu = get_cpu_for_node(t);
		if (cpu >= 0) {
			cpu_topology[cpu].package_id = package_id;
			cpu_topology[cpu].cluster_id = cluster_id;
			cpu_topology[cpu].core_id = core_id;
			cpu_topology[cpu].thread_id = i;
		} else if (cpu != -ENODEV) {
			pr_err("%pOF: Can't get CPU for thread\n", t);
			return -EINVAL;
		}
		i++;
	} while (1);

	cpu = get_cpu_for_node(core);
	if (cpu >= 0) {
		if (!leaf) {
			pr_err("%pOF: Core has both threads and CPU\n",
			       core);
			return -EINVAL;
		}

		cpu_topology[cpu].package_id = package_id;
		cpu_topology[cpu].cluster_id = cluster_id;
		cpu_topology[cpu].core_id = core_id;
	} else if (leaf && cpu != -ENODEV) {
		pr_err("%pOF: Can't get CPU for leaf core\n", core);
		return -EINVAL;
	}

	return 0;
}

static int __init parse_cluster(struct device_node *cluster, int package_id,
				int cluster_id, int depth)
{
	char name[20];
	bool leaf = true;
	bool has_cores = false;
	int core_id = 0;
	int i, ret;

	/*
	 * First check for child clusters; we currently ignore any
	 * information about the nesting of clusters and present the
	 * scheduler with a flat list of them.
	 */
	i = 0;
	do {
		snprintf(name, sizeof(name), "cluster%d", i);
		struct device_node *c __free(device_node) =
			of_get_child_by_name(cluster, name);

		if (!c)
			break;

		leaf = false;
		ret = parse_cluster(c, package_id, i, depth + 1);
		if (depth > 0)
			pr_warn("Topology for clusters of clusters not yet supported\n");
		if (ret != 0)
			return ret;
		i++;
	} while (1);

	/* Now check for cores */
	i = 0;
	do {
		snprintf(name, sizeof(name), "core%d", i);
		struct device_node *c __free(device_node) =
			of_get_child_by_name(cluster, name);

		if (!c)
			break;

		has_cores = true;

		if (depth == 0) {
			pr_err("%pOF: cpu-map children should be clusters\n", c);
			return -EINVAL;
		}

		if (leaf) {
			ret = parse_core(c, package_id, cluster_id, core_id++);
			if (ret != 0)
				return ret;
		} else {
			pr_err("%pOF: Non-leaf cluster with core %s\n",
			       cluster, name);
			return -EINVAL;
		}

		i++;
	} while (1);

	if (leaf && !has_cores)
		pr_warn("%pOF: empty cluster\n", cluster);

	return 0;
}

static int __init parse_socket(struct device_node *socket)
{
	char name[20];
	bool has_socket = false;
	int package_id = 0, ret;

	do {
		snprintf(name, sizeof(name), "socket%d", package_id);
		struct device_node *c __free(device_node) =
			of_get_child_by_name(socket, name);

		if (!c)
			break;

		has_socket = true;
		ret = parse_cluster(c, package_id, -1, 0);
		if (ret != 0)
			return ret;

		package_id++;
	} while (1);

	if (!has_socket)
		ret = parse_cluster(socket, 0, -1, 0);

	return ret;
}

static int __init parse_dt_topology(void)
{
	int ret = 0;
	int cpu;
	struct device_node *cn __free(device_node) =
		of_find_node_by_path("/cpus");

	if (!cn) {
		pr_err("No CPU information found in DT\n");
		return 0;
	}

	/*
	 * When topology is provided cpu-map is essentially a root
	 * cluster with restricted subnodes.
	 */
	struct device_node *map __free(device_node) =
		of_get_child_by_name(cn, "cpu-map");

	if (!map)
		return ret;

	ret = parse_socket(map);
	if (ret != 0)
		return ret;

	topology_normalize_cpu_scale();

	/*
	 * Check that all cores are in the topology; the SMP code will
	 * only mark cores described in the DT as possible.
	 */
	for_each_possible_cpu(cpu)
		if (cpu_topology[cpu].package_id < 0) {
			return -EINVAL;
		}

	return ret;
}
#endif

/*
 * cpu topology table
 */
struct cpu_topology cpu_topology[NR_CPUS];
EXPORT_SYMBOL_GPL(cpu_topology);

const struct cpumask *cpu_coregroup_mask(int cpu)
{
	const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));

	/* Find the smaller of NUMA, core or LLC siblings */
	if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
		/* not numa in package, lets use the package siblings */
		core_mask = &cpu_topology[cpu].core_sibling;
	}

	if (last_level_cache_is_valid(cpu)) {
		if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
			core_mask = &cpu_topology[cpu].llc_sibling;
	}

	/*
	 * For systems with no shared cpu-side LLC but with clusters defined,
	 * extend core_mask to cluster_siblings. The sched domain builder will
	 * then remove MC as redundant with CLS if SCHED_CLUSTER is enabled.
	 */
	if (IS_ENABLED(CONFIG_SCHED_CLUSTER) &&
	    cpumask_subset(core_mask, &cpu_topology[cpu].cluster_sibling))
		core_mask = &cpu_topology[cpu].cluster_sibling;

	return core_mask;
}

const struct cpumask *cpu_clustergroup_mask(int cpu)
{
	/*
	 * Forbid cpu_clustergroup_mask() to span more or the same CPUs as
	 * cpu_coregroup_mask().
	 */
	if (cpumask_subset(cpu_coregroup_mask(cpu),
			   &cpu_topology[cpu].cluster_sibling))
		return topology_sibling_cpumask(cpu);

	return &cpu_topology[cpu].cluster_sibling;
}

void update_siblings_masks(unsigned int cpuid)
{
	struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
	int cpu, ret;

	ret = detect_cache_attributes(cpuid);
	if (ret && ret != -ENOENT)
		pr_info("Early cacheinfo allocation failed, ret = %d\n", ret);

	/* update core and thread sibling masks */
	for_each_online_cpu(cpu) {
		cpu_topo = &cpu_topology[cpu];

		if (last_level_cache_is_shared(cpu, cpuid)) {
			cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
			cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
		}

		if (cpuid_topo->package_id != cpu_topo->package_id)
			continue;

		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
		cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);

		if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
			continue;

		if (cpuid_topo->cluster_id >= 0) {
			cpumask_set_cpu(cpu, &cpuid_topo->cluster_sibling);
			cpumask_set_cpu(cpuid, &cpu_topo->cluster_sibling);
		}

		if (cpuid_topo->core_id != cpu_topo->core_id)
			continue;

		cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
		cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
	}
}

static void clear_cpu_topology(int cpu)
{
	struct cpu_topology *cpu_topo = &cpu_topology[cpu];

	cpumask_clear(&cpu_topo->llc_sibling);
	cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);

	cpumask_clear(&cpu_topo->cluster_sibling);
	cpumask_set_cpu(cpu, &cpu_topo->cluster_sibling);

	cpumask_clear(&cpu_topo->core_sibling);
	cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
	cpumask_clear(&cpu_topo->thread_sibling);
	cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
}

void __init reset_cpu_topology(void)
{
	unsigned int cpu;

	for_each_possible_cpu(cpu) {
		struct cpu_topology *cpu_topo = &cpu_topology[cpu];

		cpu_topo->thread_id = -1;
		cpu_topo->core_id = -1;
		cpu_topo->cluster_id = -1;
		cpu_topo->package_id = -1;

		clear_cpu_topology(cpu);
	}
}

void remove_cpu_topology(unsigned int cpu)
{
	int sibling;

	for_each_cpu(sibling, topology_core_cpumask(cpu))
		cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
	for_each_cpu(sibling, topology_sibling_cpumask(cpu))
		cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
	for_each_cpu(sibling, topology_cluster_cpumask(cpu))
		cpumask_clear_cpu(cpu, topology_cluster_cpumask(sibling));
	for_each_cpu(sibling, topology_llc_cpumask(cpu))
		cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));

	clear_cpu_topology(cpu);
}

__weak int __init parse_acpi_topology(void)
{
	return 0;
}

#if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
void __init init_cpu_topology(void)
{
	int cpu, ret;

	reset_cpu_topology();
	ret = parse_acpi_topology();
	if (!ret)
		ret = of_have_populated_dt() && parse_dt_topology();

	if (ret) {
		/*
		 * Discard anything that was parsed if we hit an error so we
		 * don't use partial information. But do not return yet to give
		 * arch-specific early cache level detection a chance to run.
		 */
		reset_cpu_topology();
	}

	for_each_possible_cpu(cpu) {
		ret = fetch_cache_info(cpu);
		if (!ret)
			continue;
		else if (ret != -ENOENT)
			pr_err("Early cacheinfo failed, ret = %d\n", ret);
		return;
	}
}

void store_cpu_topology(unsigned int cpuid)
{
	struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];

	if (cpuid_topo->package_id != -1)
		goto topology_populated;

	cpuid_topo->thread_id = -1;
	cpuid_topo->core_id = cpuid;
	cpuid_topo->package_id = cpu_to_node(cpuid);

	pr_debug("CPU%u: package %d core %d thread %d\n",
		 cpuid, cpuid_topo->package_id, cpuid_topo->core_id,
		 cpuid_topo->thread_id);

topology_populated:
	update_siblings_masks(cpuid);
}
#endif