xref: /linux/drivers/base/arch_topology.c (revision 14062c267f09c7b33a8d5a7d9eb3908b9941aae4)
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/cacheinfo.h>
11 #include <linux/cleanup.h>
12 #include <linux/cpu.h>
13 #include <linux/cpufreq.h>
14 #include <linux/device.h>
15 #include <linux/of.h>
16 #include <linux/slab.h>
17 #include <linux/sched/topology.h>
18 #include <linux/cpuset.h>
19 #include <linux/cpumask.h>
20 #include <linux/init.h>
21 #include <linux/rcupdate.h>
22 #include <linux/sched.h>
23 #include <linux/units.h>
24 
25 #define CREATE_TRACE_POINTS
26 #include <trace/events/hw_pressure.h>
27 
28 static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data);
29 static struct cpumask scale_freq_counters_mask;
30 static bool scale_freq_invariant;
31 DEFINE_PER_CPU(unsigned long, capacity_freq_ref) = 1;
32 EXPORT_PER_CPU_SYMBOL_GPL(capacity_freq_ref);
33 
supports_scale_freq_counters(const struct cpumask * cpus)34 static bool supports_scale_freq_counters(const struct cpumask *cpus)
35 {
36 	return cpumask_subset(cpus, &scale_freq_counters_mask);
37 }
38 
topology_scale_freq_invariant(void)39 bool topology_scale_freq_invariant(void)
40 {
41 	return cpufreq_supports_freq_invariance() ||
42 	       supports_scale_freq_counters(cpu_online_mask);
43 }
44 
update_scale_freq_invariant(bool status)45 static void update_scale_freq_invariant(bool status)
46 {
47 	if (scale_freq_invariant == status)
48 		return;
49 
50 	/*
51 	 * Task scheduler behavior depends on frequency invariance support,
52 	 * either cpufreq or counter driven. If the support status changes as
53 	 * a result of counter initialisation and use, retrigger the build of
54 	 * scheduling domains to ensure the information is propagated properly.
55 	 */
56 	if (topology_scale_freq_invariant() == status) {
57 		scale_freq_invariant = status;
58 		rebuild_sched_domains_energy();
59 	}
60 }
61 
topology_set_scale_freq_source(struct scale_freq_data * data,const struct cpumask * cpus)62 void topology_set_scale_freq_source(struct scale_freq_data *data,
63 				    const struct cpumask *cpus)
64 {
65 	struct scale_freq_data *sfd;
66 	int cpu;
67 
68 	/*
69 	 * Avoid calling rebuild_sched_domains() unnecessarily if FIE is
70 	 * supported by cpufreq.
71 	 */
72 	if (cpumask_empty(&scale_freq_counters_mask))
73 		scale_freq_invariant = topology_scale_freq_invariant();
74 
75 	rcu_read_lock();
76 
77 	for_each_cpu(cpu, cpus) {
78 		sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
79 
80 		/* Use ARCH provided counters whenever possible */
81 		if (!sfd || sfd->source != SCALE_FREQ_SOURCE_ARCH) {
82 			rcu_assign_pointer(per_cpu(sft_data, cpu), data);
83 			cpumask_set_cpu(cpu, &scale_freq_counters_mask);
84 		}
85 	}
86 
87 	rcu_read_unlock();
88 
89 	update_scale_freq_invariant(true);
90 }
91 EXPORT_SYMBOL_GPL(topology_set_scale_freq_source);
92 
topology_clear_scale_freq_source(enum scale_freq_source source,const struct cpumask * cpus)93 void topology_clear_scale_freq_source(enum scale_freq_source source,
94 				      const struct cpumask *cpus)
95 {
96 	struct scale_freq_data *sfd;
97 	int cpu;
98 
99 	rcu_read_lock();
100 
101 	for_each_cpu(cpu, cpus) {
102 		sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
103 
104 		if (sfd && sfd->source == source) {
105 			rcu_assign_pointer(per_cpu(sft_data, cpu), NULL);
106 			cpumask_clear_cpu(cpu, &scale_freq_counters_mask);
107 		}
108 	}
109 
110 	rcu_read_unlock();
111 
112 	/*
113 	 * Make sure all references to previous sft_data are dropped to avoid
114 	 * use-after-free races.
115 	 */
116 	synchronize_rcu();
117 
118 	update_scale_freq_invariant(false);
119 }
120 EXPORT_SYMBOL_GPL(topology_clear_scale_freq_source);
121 
topology_scale_freq_tick(void)122 void topology_scale_freq_tick(void)
123 {
124 	struct scale_freq_data *sfd = rcu_dereference_sched(*this_cpu_ptr(&sft_data));
125 
126 	if (sfd)
127 		sfd->set_freq_scale();
128 }
129 
130 DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
131 EXPORT_PER_CPU_SYMBOL_GPL(arch_freq_scale);
132 
topology_set_freq_scale(const struct cpumask * cpus,unsigned long cur_freq,unsigned long max_freq)133 void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq,
134 			     unsigned long max_freq)
135 {
136 	unsigned long scale;
137 	int i;
138 
139 	if (WARN_ON_ONCE(!cur_freq || !max_freq))
140 		return;
141 
142 	/*
143 	 * If the use of counters for FIE is enabled, just return as we don't
144 	 * want to update the scale factor with information from CPUFREQ.
145 	 * Instead the scale factor will be updated from arch_scale_freq_tick.
146 	 */
147 	if (supports_scale_freq_counters(cpus))
148 		return;
149 
150 	scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;
151 
152 	for_each_cpu(i, cpus)
153 		per_cpu(arch_freq_scale, i) = scale;
154 }
155 
156 DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
157 EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);
158 
topology_set_cpu_scale(unsigned int cpu,unsigned long capacity)159 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
160 {
161 	per_cpu(cpu_scale, cpu) = capacity;
162 }
163 
164 DEFINE_PER_CPU(unsigned long, hw_pressure);
165 
166 /**
167  * topology_update_hw_pressure() - Update HW pressure for CPUs
168  * @cpus        : The related CPUs for which capacity has been reduced
169  * @capped_freq : The maximum allowed frequency that CPUs can run at
170  *
171  * Update the value of HW pressure for all @cpus in the mask. The
172  * cpumask should include all (online+offline) affected CPUs, to avoid
173  * operating on stale data when hot-plug is used for some CPUs. The
174  * @capped_freq reflects the currently allowed max CPUs frequency due to
175  * HW capping. It might be also a boost frequency value, which is bigger
176  * than the internal 'capacity_freq_ref' max frequency. In such case the
177  * pressure value should simply be removed, since this is an indication that
178  * there is no HW throttling. The @capped_freq must be provided in kHz.
179  */
topology_update_hw_pressure(const struct cpumask * cpus,unsigned long capped_freq)180 void topology_update_hw_pressure(const struct cpumask *cpus,
181 				      unsigned long capped_freq)
182 {
183 	unsigned long max_capacity, capacity, pressure;
184 	u32 max_freq;
185 	int cpu;
186 
187 	cpu = cpumask_first(cpus);
188 	max_capacity = arch_scale_cpu_capacity(cpu);
189 	max_freq = arch_scale_freq_ref(cpu);
190 
191 	/*
192 	 * Handle properly the boost frequencies, which should simply clean
193 	 * the HW pressure value.
194 	 */
195 	if (max_freq <= capped_freq)
196 		capacity = max_capacity;
197 	else
198 		capacity = mult_frac(max_capacity, capped_freq, max_freq);
199 
200 	pressure = max_capacity - capacity;
201 
202 	trace_hw_pressure_update(cpu, pressure);
203 
204 	for_each_cpu(cpu, cpus)
205 		WRITE_ONCE(per_cpu(hw_pressure, cpu), pressure);
206 }
207 EXPORT_SYMBOL_GPL(topology_update_hw_pressure);
208 
cpu_capacity_show(struct device * dev,struct device_attribute * attr,char * buf)209 static ssize_t cpu_capacity_show(struct device *dev,
210 				 struct device_attribute *attr,
211 				 char *buf)
212 {
213 	struct cpu *cpu = container_of(dev, struct cpu, dev);
214 
215 	return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
216 }
217 
218 static void update_topology_flags_workfn(struct work_struct *work);
219 static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
220 
221 static DEVICE_ATTR_RO(cpu_capacity);
222 
cpu_capacity_sysctl_add(unsigned int cpu)223 static int cpu_capacity_sysctl_add(unsigned int cpu)
224 {
225 	struct device *cpu_dev = get_cpu_device(cpu);
226 
227 	if (!cpu_dev)
228 		return -ENOENT;
229 
230 	device_create_file(cpu_dev, &dev_attr_cpu_capacity);
231 
232 	return 0;
233 }
234 
cpu_capacity_sysctl_remove(unsigned int cpu)235 static int cpu_capacity_sysctl_remove(unsigned int cpu)
236 {
237 	struct device *cpu_dev = get_cpu_device(cpu);
238 
239 	if (!cpu_dev)
240 		return -ENOENT;
241 
242 	device_remove_file(cpu_dev, &dev_attr_cpu_capacity);
243 
244 	return 0;
245 }
246 
register_cpu_capacity_sysctl(void)247 static int register_cpu_capacity_sysctl(void)
248 {
249 	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "topology/cpu-capacity",
250 			  cpu_capacity_sysctl_add, cpu_capacity_sysctl_remove);
251 
252 	return 0;
253 }
254 subsys_initcall(register_cpu_capacity_sysctl);
255 
256 static int update_topology;
257 
topology_update_cpu_topology(void)258 int topology_update_cpu_topology(void)
259 {
260 	return update_topology;
261 }
262 
263 /*
264  * Updating the sched_domains can't be done directly from cpufreq callbacks
265  * due to locking, so queue the work for later.
266  */
update_topology_flags_workfn(struct work_struct * work)267 static void update_topology_flags_workfn(struct work_struct *work)
268 {
269 	update_topology = 1;
270 	rebuild_sched_domains();
271 	pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
272 	update_topology = 0;
273 }
274 
275 static u32 *raw_capacity;
276 
free_raw_capacity(void)277 static int free_raw_capacity(void)
278 {
279 	kfree(raw_capacity);
280 	raw_capacity = NULL;
281 
282 	return 0;
283 }
284 
topology_normalize_cpu_scale(void)285 void topology_normalize_cpu_scale(void)
286 {
287 	u64 capacity;
288 	u64 capacity_scale;
289 	int cpu;
290 
291 	if (!raw_capacity)
292 		return;
293 
294 	capacity_scale = 1;
295 	for_each_possible_cpu(cpu) {
296 		capacity = raw_capacity[cpu] * per_cpu(capacity_freq_ref, cpu);
297 		capacity_scale = max(capacity, capacity_scale);
298 	}
299 
300 	pr_debug("cpu_capacity: capacity_scale=%llu\n", capacity_scale);
301 	for_each_possible_cpu(cpu) {
302 		capacity = raw_capacity[cpu] * per_cpu(capacity_freq_ref, cpu);
303 		capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT,
304 			capacity_scale);
305 		topology_set_cpu_scale(cpu, capacity);
306 		pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
307 			cpu, topology_get_cpu_scale(cpu));
308 	}
309 }
310 
topology_parse_cpu_capacity(struct device_node * cpu_node,int cpu)311 bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
312 {
313 	struct clk *cpu_clk;
314 	static bool cap_parsing_failed;
315 	int ret;
316 	u32 cpu_capacity;
317 
318 	if (cap_parsing_failed)
319 		return false;
320 
321 	ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
322 				   &cpu_capacity);
323 	if (!ret) {
324 		if (!raw_capacity) {
325 			raw_capacity = kcalloc(num_possible_cpus(),
326 					       sizeof(*raw_capacity),
327 					       GFP_KERNEL);
328 			if (!raw_capacity) {
329 				cap_parsing_failed = true;
330 				return false;
331 			}
332 		}
333 		raw_capacity[cpu] = cpu_capacity;
334 		pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
335 			cpu_node, raw_capacity[cpu]);
336 
337 		/*
338 		 * Update capacity_freq_ref for calculating early boot CPU capacities.
339 		 * For non-clk CPU DVFS mechanism, there's no way to get the
340 		 * frequency value now, assuming they are running at the same
341 		 * frequency (by keeping the initial capacity_freq_ref value).
342 		 */
343 		cpu_clk = of_clk_get(cpu_node, 0);
344 		if (!PTR_ERR_OR_ZERO(cpu_clk)) {
345 			per_cpu(capacity_freq_ref, cpu) =
346 				clk_get_rate(cpu_clk) / HZ_PER_KHZ;
347 			clk_put(cpu_clk);
348 		}
349 	} else {
350 		if (raw_capacity) {
351 			pr_err("cpu_capacity: missing %pOF raw capacity\n",
352 				cpu_node);
353 			pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
354 		}
355 		cap_parsing_failed = true;
356 		free_raw_capacity();
357 	}
358 
359 	return !ret;
360 }
361 
freq_inv_set_max_ratio(int cpu,u64 max_rate)362 void __weak freq_inv_set_max_ratio(int cpu, u64 max_rate)
363 {
364 }
365 
366 #ifdef CONFIG_ACPI_CPPC_LIB
367 #include <acpi/cppc_acpi.h>
368 
topology_init_cpu_capacity_cppc(void)369 static inline void topology_init_cpu_capacity_cppc(void)
370 {
371 	u64 capacity, capacity_scale = 0;
372 	struct cppc_perf_caps perf_caps;
373 	int cpu;
374 
375 	if (likely(!acpi_cpc_valid()))
376 		return;
377 
378 	raw_capacity = kcalloc(num_possible_cpus(), sizeof(*raw_capacity),
379 			       GFP_KERNEL);
380 	if (!raw_capacity)
381 		return;
382 
383 	for_each_possible_cpu(cpu) {
384 		if (!cppc_get_perf_caps(cpu, &perf_caps) &&
385 		    (perf_caps.highest_perf >= perf_caps.nominal_perf) &&
386 		    (perf_caps.highest_perf >= perf_caps.lowest_perf)) {
387 			raw_capacity[cpu] = perf_caps.highest_perf;
388 			capacity_scale = max_t(u64, capacity_scale, raw_capacity[cpu]);
389 
390 			per_cpu(capacity_freq_ref, cpu) = cppc_perf_to_khz(&perf_caps, raw_capacity[cpu]);
391 
392 			pr_debug("cpu_capacity: CPU%d cpu_capacity=%u (raw).\n",
393 				 cpu, raw_capacity[cpu]);
394 			continue;
395 		}
396 
397 		pr_err("cpu_capacity: CPU%d missing/invalid highest performance.\n", cpu);
398 		pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
399 		goto exit;
400 	}
401 
402 	for_each_possible_cpu(cpu) {
403 		freq_inv_set_max_ratio(cpu,
404 				       per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ);
405 
406 		capacity = raw_capacity[cpu];
407 		capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT,
408 				     capacity_scale);
409 		topology_set_cpu_scale(cpu, capacity);
410 		pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
411 			cpu, topology_get_cpu_scale(cpu));
412 	}
413 
414 	schedule_work(&update_topology_flags_work);
415 	pr_debug("cpu_capacity: cpu_capacity initialization done\n");
416 
417 exit:
418 	free_raw_capacity();
419 }
acpi_processor_init_invariance_cppc(void)420 void acpi_processor_init_invariance_cppc(void)
421 {
422 	topology_init_cpu_capacity_cppc();
423 }
424 #endif
425 
426 #ifdef CONFIG_CPU_FREQ
427 static cpumask_var_t cpus_to_visit;
428 static void parsing_done_workfn(struct work_struct *work);
429 static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
430 
431 static int
init_cpu_capacity_callback(struct notifier_block * nb,unsigned long val,void * data)432 init_cpu_capacity_callback(struct notifier_block *nb,
433 			   unsigned long val,
434 			   void *data)
435 {
436 	struct cpufreq_policy *policy = data;
437 	int cpu;
438 
439 	if (val != CPUFREQ_CREATE_POLICY)
440 		return 0;
441 
442 	pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
443 		 cpumask_pr_args(policy->related_cpus),
444 		 cpumask_pr_args(cpus_to_visit));
445 
446 	cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
447 
448 	for_each_cpu(cpu, policy->related_cpus) {
449 		per_cpu(capacity_freq_ref, cpu) = policy->cpuinfo.max_freq;
450 		freq_inv_set_max_ratio(cpu,
451 				       per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ);
452 	}
453 
454 	if (cpumask_empty(cpus_to_visit)) {
455 		if (raw_capacity) {
456 			topology_normalize_cpu_scale();
457 			schedule_work(&update_topology_flags_work);
458 			free_raw_capacity();
459 		}
460 		pr_debug("cpu_capacity: parsing done\n");
461 		schedule_work(&parsing_done_work);
462 	}
463 
464 	return 0;
465 }
466 
467 static struct notifier_block init_cpu_capacity_notifier = {
468 	.notifier_call = init_cpu_capacity_callback,
469 };
470 
register_cpufreq_notifier(void)471 static int __init register_cpufreq_notifier(void)
472 {
473 	int ret;
474 
475 	/*
476 	 * On ACPI-based systems skip registering cpufreq notifier as cpufreq
477 	 * information is not needed for cpu capacity initialization.
478 	 */
479 	if (!acpi_disabled)
480 		return -EINVAL;
481 
482 	if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL))
483 		return -ENOMEM;
484 
485 	cpumask_copy(cpus_to_visit, cpu_possible_mask);
486 
487 	ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
488 					CPUFREQ_POLICY_NOTIFIER);
489 
490 	if (ret)
491 		free_cpumask_var(cpus_to_visit);
492 
493 	return ret;
494 }
495 core_initcall(register_cpufreq_notifier);
496 
parsing_done_workfn(struct work_struct * work)497 static void parsing_done_workfn(struct work_struct *work)
498 {
499 	cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
500 					 CPUFREQ_POLICY_NOTIFIER);
501 	free_cpumask_var(cpus_to_visit);
502 }
503 
504 #else
505 core_initcall(free_raw_capacity);
506 #endif
507 
508 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
509 /*
510  * This function returns the logic cpu number of the node.
511  * There are basically three kinds of return values:
512  * (1) logic cpu number which is > 0.
513  * (2) -ENODEV when the device tree(DT) node is valid and found in the DT but
514  * there is no possible logical CPU in the kernel to match. This happens
515  * when CONFIG_NR_CPUS is configure to be smaller than the number of
516  * CPU nodes in DT. We need to just ignore this case.
517  * (3) -1 if the node does not exist in the device tree
518  */
get_cpu_for_node(struct device_node * node)519 static int __init get_cpu_for_node(struct device_node *node)
520 {
521 	int cpu;
522 	struct device_node *cpu_node __free(device_node) =
523 		of_parse_phandle(node, "cpu", 0);
524 
525 	if (!cpu_node)
526 		return -1;
527 
528 	cpu = of_cpu_node_to_id(cpu_node);
529 	if (cpu >= 0)
530 		topology_parse_cpu_capacity(cpu_node, cpu);
531 	else
532 		pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n",
533 			cpu_node, cpumask_pr_args(cpu_possible_mask));
534 
535 	return cpu;
536 }
537 
parse_core(struct device_node * core,int package_id,int cluster_id,int core_id)538 static int __init parse_core(struct device_node *core, int package_id,
539 			     int cluster_id, int core_id)
540 {
541 	char name[20];
542 	bool leaf = true;
543 	int i = 0;
544 	int cpu;
545 
546 	do {
547 		snprintf(name, sizeof(name), "thread%d", i);
548 		struct device_node *t __free(device_node) =
549 			of_get_child_by_name(core, name);
550 
551 		if (!t)
552 			break;
553 
554 		leaf = false;
555 		cpu = get_cpu_for_node(t);
556 		if (cpu >= 0) {
557 			cpu_topology[cpu].package_id = package_id;
558 			cpu_topology[cpu].cluster_id = cluster_id;
559 			cpu_topology[cpu].core_id = core_id;
560 			cpu_topology[cpu].thread_id = i;
561 		} else if (cpu != -ENODEV) {
562 			pr_err("%pOF: Can't get CPU for thread\n", t);
563 			return -EINVAL;
564 		}
565 		i++;
566 	} while (1);
567 
568 	cpu = get_cpu_for_node(core);
569 	if (cpu >= 0) {
570 		if (!leaf) {
571 			pr_err("%pOF: Core has both threads and CPU\n",
572 			       core);
573 			return -EINVAL;
574 		}
575 
576 		cpu_topology[cpu].package_id = package_id;
577 		cpu_topology[cpu].cluster_id = cluster_id;
578 		cpu_topology[cpu].core_id = core_id;
579 	} else if (leaf && cpu != -ENODEV) {
580 		pr_err("%pOF: Can't get CPU for leaf core\n", core);
581 		return -EINVAL;
582 	}
583 
584 	return 0;
585 }
586 
parse_cluster(struct device_node * cluster,int package_id,int cluster_id,int depth)587 static int __init parse_cluster(struct device_node *cluster, int package_id,
588 				int cluster_id, int depth)
589 {
590 	char name[20];
591 	bool leaf = true;
592 	bool has_cores = false;
593 	int core_id = 0;
594 	int i, ret;
595 
596 	/*
597 	 * First check for child clusters; we currently ignore any
598 	 * information about the nesting of clusters and present the
599 	 * scheduler with a flat list of them.
600 	 */
601 	i = 0;
602 	do {
603 		snprintf(name, sizeof(name), "cluster%d", i);
604 		struct device_node *c __free(device_node) =
605 			of_get_child_by_name(cluster, name);
606 
607 		if (!c)
608 			break;
609 
610 		leaf = false;
611 		ret = parse_cluster(c, package_id, i, depth + 1);
612 		if (depth > 0)
613 			pr_warn("Topology for clusters of clusters not yet supported\n");
614 		if (ret != 0)
615 			return ret;
616 		i++;
617 	} while (1);
618 
619 	/* Now check for cores */
620 	i = 0;
621 	do {
622 		snprintf(name, sizeof(name), "core%d", i);
623 		struct device_node *c __free(device_node) =
624 			of_get_child_by_name(cluster, name);
625 
626 		if (!c)
627 			break;
628 
629 		has_cores = true;
630 
631 		if (depth == 0) {
632 			pr_err("%pOF: cpu-map children should be clusters\n", c);
633 			return -EINVAL;
634 		}
635 
636 		if (leaf) {
637 			ret = parse_core(c, package_id, cluster_id, core_id++);
638 			if (ret != 0)
639 				return ret;
640 		} else {
641 			pr_err("%pOF: Non-leaf cluster with core %s\n",
642 			       cluster, name);
643 			return -EINVAL;
644 		}
645 
646 		i++;
647 	} while (1);
648 
649 	if (leaf && !has_cores)
650 		pr_warn("%pOF: empty cluster\n", cluster);
651 
652 	return 0;
653 }
654 
parse_socket(struct device_node * socket)655 static int __init parse_socket(struct device_node *socket)
656 {
657 	char name[20];
658 	bool has_socket = false;
659 	int package_id = 0, ret;
660 
661 	do {
662 		snprintf(name, sizeof(name), "socket%d", package_id);
663 		struct device_node *c __free(device_node) =
664 			of_get_child_by_name(socket, name);
665 
666 		if (!c)
667 			break;
668 
669 		has_socket = true;
670 		ret = parse_cluster(c, package_id, -1, 0);
671 		if (ret != 0)
672 			return ret;
673 
674 		package_id++;
675 	} while (1);
676 
677 	if (!has_socket)
678 		ret = parse_cluster(socket, 0, -1, 0);
679 
680 	return ret;
681 }
682 
parse_dt_topology(void)683 static int __init parse_dt_topology(void)
684 {
685 	int ret = 0;
686 	int cpu;
687 	struct device_node *cn __free(device_node) =
688 		of_find_node_by_path("/cpus");
689 
690 	if (!cn) {
691 		pr_err("No CPU information found in DT\n");
692 		return 0;
693 	}
694 
695 	/*
696 	 * When topology is provided cpu-map is essentially a root
697 	 * cluster with restricted subnodes.
698 	 */
699 	struct device_node *map __free(device_node) =
700 		of_get_child_by_name(cn, "cpu-map");
701 
702 	if (!map)
703 		return ret;
704 
705 	ret = parse_socket(map);
706 	if (ret != 0)
707 		return ret;
708 
709 	topology_normalize_cpu_scale();
710 
711 	/*
712 	 * Check that all cores are in the topology; the SMP code will
713 	 * only mark cores described in the DT as possible.
714 	 */
715 	for_each_possible_cpu(cpu)
716 		if (cpu_topology[cpu].package_id < 0) {
717 			return -EINVAL;
718 		}
719 
720 	return ret;
721 }
722 #endif
723 
724 /*
725  * cpu topology table
726  */
727 struct cpu_topology cpu_topology[NR_CPUS];
728 EXPORT_SYMBOL_GPL(cpu_topology);
729 
cpu_coregroup_mask(int cpu)730 const struct cpumask *cpu_coregroup_mask(int cpu)
731 {
732 	const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));
733 
734 	/* Find the smaller of NUMA, core or LLC siblings */
735 	if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
736 		/* not numa in package, lets use the package siblings */
737 		core_mask = &cpu_topology[cpu].core_sibling;
738 	}
739 
740 	if (last_level_cache_is_valid(cpu)) {
741 		if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
742 			core_mask = &cpu_topology[cpu].llc_sibling;
743 	}
744 
745 	/*
746 	 * For systems with no shared cpu-side LLC but with clusters defined,
747 	 * extend core_mask to cluster_siblings. The sched domain builder will
748 	 * then remove MC as redundant with CLS if SCHED_CLUSTER is enabled.
749 	 */
750 	if (IS_ENABLED(CONFIG_SCHED_CLUSTER) &&
751 	    cpumask_subset(core_mask, &cpu_topology[cpu].cluster_sibling))
752 		core_mask = &cpu_topology[cpu].cluster_sibling;
753 
754 	return core_mask;
755 }
756 
cpu_clustergroup_mask(int cpu)757 const struct cpumask *cpu_clustergroup_mask(int cpu)
758 {
759 	/*
760 	 * Forbid cpu_clustergroup_mask() to span more or the same CPUs as
761 	 * cpu_coregroup_mask().
762 	 */
763 	if (cpumask_subset(cpu_coregroup_mask(cpu),
764 			   &cpu_topology[cpu].cluster_sibling))
765 		return topology_sibling_cpumask(cpu);
766 
767 	return &cpu_topology[cpu].cluster_sibling;
768 }
769 
update_siblings_masks(unsigned int cpuid)770 void update_siblings_masks(unsigned int cpuid)
771 {
772 	struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
773 	int cpu, ret;
774 
775 	ret = detect_cache_attributes(cpuid);
776 	if (ret && ret != -ENOENT)
777 		pr_info("Early cacheinfo allocation failed, ret = %d\n", ret);
778 
779 	/* update core and thread sibling masks */
780 	for_each_online_cpu(cpu) {
781 		cpu_topo = &cpu_topology[cpu];
782 
783 		if (last_level_cache_is_shared(cpu, cpuid)) {
784 			cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
785 			cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
786 		}
787 
788 		if (cpuid_topo->package_id != cpu_topo->package_id)
789 			continue;
790 
791 		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
792 		cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
793 
794 		if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
795 			continue;
796 
797 		if (cpuid_topo->cluster_id >= 0) {
798 			cpumask_set_cpu(cpu, &cpuid_topo->cluster_sibling);
799 			cpumask_set_cpu(cpuid, &cpu_topo->cluster_sibling);
800 		}
801 
802 		if (cpuid_topo->core_id != cpu_topo->core_id)
803 			continue;
804 
805 		cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
806 		cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
807 	}
808 }
809 
clear_cpu_topology(int cpu)810 static void clear_cpu_topology(int cpu)
811 {
812 	struct cpu_topology *cpu_topo = &cpu_topology[cpu];
813 
814 	cpumask_clear(&cpu_topo->llc_sibling);
815 	cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);
816 
817 	cpumask_clear(&cpu_topo->cluster_sibling);
818 	cpumask_set_cpu(cpu, &cpu_topo->cluster_sibling);
819 
820 	cpumask_clear(&cpu_topo->core_sibling);
821 	cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
822 	cpumask_clear(&cpu_topo->thread_sibling);
823 	cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
824 }
825 
reset_cpu_topology(void)826 void __init reset_cpu_topology(void)
827 {
828 	unsigned int cpu;
829 
830 	for_each_possible_cpu(cpu) {
831 		struct cpu_topology *cpu_topo = &cpu_topology[cpu];
832 
833 		cpu_topo->thread_id = -1;
834 		cpu_topo->core_id = -1;
835 		cpu_topo->cluster_id = -1;
836 		cpu_topo->package_id = -1;
837 
838 		clear_cpu_topology(cpu);
839 	}
840 }
841 
remove_cpu_topology(unsigned int cpu)842 void remove_cpu_topology(unsigned int cpu)
843 {
844 	int sibling;
845 
846 	for_each_cpu(sibling, topology_core_cpumask(cpu))
847 		cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
848 	for_each_cpu(sibling, topology_sibling_cpumask(cpu))
849 		cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
850 	for_each_cpu(sibling, topology_cluster_cpumask(cpu))
851 		cpumask_clear_cpu(cpu, topology_cluster_cpumask(sibling));
852 	for_each_cpu(sibling, topology_llc_cpumask(cpu))
853 		cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));
854 
855 	clear_cpu_topology(cpu);
856 }
857 
parse_acpi_topology(void)858 __weak int __init parse_acpi_topology(void)
859 {
860 	return 0;
861 }
862 
863 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
init_cpu_topology(void)864 void __init init_cpu_topology(void)
865 {
866 	int cpu, ret;
867 
868 	reset_cpu_topology();
869 	ret = parse_acpi_topology();
870 	if (!ret)
871 		ret = of_have_populated_dt() && parse_dt_topology();
872 
873 	if (ret) {
874 		/*
875 		 * Discard anything that was parsed if we hit an error so we
876 		 * don't use partial information. But do not return yet to give
877 		 * arch-specific early cache level detection a chance to run.
878 		 */
879 		reset_cpu_topology();
880 	}
881 
882 	for_each_possible_cpu(cpu) {
883 		ret = fetch_cache_info(cpu);
884 		if (!ret)
885 			continue;
886 		else if (ret != -ENOENT)
887 			pr_err("Early cacheinfo failed, ret = %d\n", ret);
888 		return;
889 	}
890 }
891 
store_cpu_topology(unsigned int cpuid)892 void store_cpu_topology(unsigned int cpuid)
893 {
894 	struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
895 
896 	if (cpuid_topo->package_id != -1)
897 		goto topology_populated;
898 
899 	cpuid_topo->thread_id = -1;
900 	cpuid_topo->core_id = cpuid;
901 	cpuid_topo->package_id = cpu_to_node(cpuid);
902 
903 	pr_debug("CPU%u: package %d core %d thread %d\n",
904 		 cpuid, cpuid_topo->package_id, cpuid_topo->core_id,
905 		 cpuid_topo->thread_id);
906 
907 topology_populated:
908 	update_siblings_masks(cpuid);
909 }
910 #endif
911