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/cpu_smt.h>
15 #include <linux/device.h>
16 #include <linux/of.h>
17 #include <linux/slab.h>
18 #include <linux/sched/topology.h>
19 #include <linux/cpuset.h>
20 #include <linux/cpumask.h>
21 #include <linux/init.h>
22 #include <linux/rcupdate.h>
23 #include <linux/sched.h>
24 #include <linux/units.h>
25 
26 #define CREATE_TRACE_POINTS
27 #include <trace/events/hw_pressure.h>
28 
29 static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data);
30 static struct cpumask scale_freq_counters_mask;
31 static bool scale_freq_invariant;
32 DEFINE_PER_CPU(unsigned long, capacity_freq_ref) = 0;
33 EXPORT_PER_CPU_SYMBOL_GPL(capacity_freq_ref);
34 
supports_scale_freq_counters(const struct cpumask * cpus)35 static bool supports_scale_freq_counters(const struct cpumask *cpus)
36 {
37 	return cpumask_subset(cpus, &scale_freq_counters_mask);
38 }
39 
topology_scale_freq_invariant(void)40 bool topology_scale_freq_invariant(void)
41 {
42 	return cpufreq_supports_freq_invariance() ||
43 	       supports_scale_freq_counters(cpu_online_mask);
44 }
45 
update_scale_freq_invariant(bool status)46 static void update_scale_freq_invariant(bool status)
47 {
48 	if (scale_freq_invariant == status)
49 		return;
50 
51 	/*
52 	 * Task scheduler behavior depends on frequency invariance support,
53 	 * either cpufreq or counter driven. If the support status changes as
54 	 * a result of counter initialisation and use, retrigger the build of
55 	 * scheduling domains to ensure the information is propagated properly.
56 	 */
57 	if (topology_scale_freq_invariant() == status) {
58 		scale_freq_invariant = status;
59 		rebuild_sched_domains_energy();
60 	}
61 }
62 
topology_set_scale_freq_source(struct scale_freq_data * data,const struct cpumask * cpus)63 void topology_set_scale_freq_source(struct scale_freq_data *data,
64 				    const struct cpumask *cpus)
65 {
66 	struct scale_freq_data *sfd;
67 	int cpu;
68 
69 	/*
70 	 * Avoid calling rebuild_sched_domains() unnecessarily if FIE is
71 	 * supported by cpufreq.
72 	 */
73 	if (cpumask_empty(&scale_freq_counters_mask))
74 		scale_freq_invariant = topology_scale_freq_invariant();
75 
76 	rcu_read_lock();
77 
78 	for_each_cpu(cpu, cpus) {
79 		sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
80 
81 		/* Use ARCH provided counters whenever possible */
82 		if (!sfd || sfd->source != SCALE_FREQ_SOURCE_ARCH) {
83 			rcu_assign_pointer(per_cpu(sft_data, cpu), data);
84 			cpumask_set_cpu(cpu, &scale_freq_counters_mask);
85 		}
86 	}
87 
88 	rcu_read_unlock();
89 
90 	update_scale_freq_invariant(true);
91 }
92 EXPORT_SYMBOL_GPL(topology_set_scale_freq_source);
93 
topology_clear_scale_freq_source(enum scale_freq_source source,const struct cpumask * cpus)94 void topology_clear_scale_freq_source(enum scale_freq_source source,
95 				      const struct cpumask *cpus)
96 {
97 	struct scale_freq_data *sfd;
98 	int cpu;
99 
100 	rcu_read_lock();
101 
102 	for_each_cpu(cpu, cpus) {
103 		sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
104 
105 		if (sfd && sfd->source == source) {
106 			rcu_assign_pointer(per_cpu(sft_data, cpu), NULL);
107 			cpumask_clear_cpu(cpu, &scale_freq_counters_mask);
108 		}
109 	}
110 
111 	rcu_read_unlock();
112 
113 	/*
114 	 * Make sure all references to previous sft_data are dropped to avoid
115 	 * use-after-free races.
116 	 */
117 	synchronize_rcu();
118 
119 	update_scale_freq_invariant(false);
120 }
121 EXPORT_SYMBOL_GPL(topology_clear_scale_freq_source);
122 
topology_scale_freq_tick(void)123 void topology_scale_freq_tick(void)
124 {
125 	struct scale_freq_data *sfd = rcu_dereference_sched(*this_cpu_ptr(&sft_data));
126 
127 	if (sfd)
128 		sfd->set_freq_scale();
129 }
130 
131 DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
132 EXPORT_PER_CPU_SYMBOL_GPL(arch_freq_scale);
133 
topology_set_freq_scale(const struct cpumask * cpus,unsigned long cur_freq,unsigned long max_freq)134 void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq,
135 			     unsigned long max_freq)
136 {
137 	unsigned long scale;
138 	int i;
139 
140 	if (WARN_ON_ONCE(!cur_freq || !max_freq))
141 		return;
142 
143 	/*
144 	 * If the use of counters for FIE is enabled, just return as we don't
145 	 * want to update the scale factor with information from CPUFREQ.
146 	 * Instead the scale factor will be updated from arch_scale_freq_tick.
147 	 */
148 	if (supports_scale_freq_counters(cpus))
149 		return;
150 
151 	scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;
152 
153 	for_each_cpu(i, cpus)
154 		per_cpu(arch_freq_scale, i) = scale;
155 }
156 
157 DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
158 EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);
159 
topology_set_cpu_scale(unsigned int cpu,unsigned long capacity)160 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
161 {
162 	per_cpu(cpu_scale, cpu) = capacity;
163 }
164 
165 DEFINE_PER_CPU(unsigned long, hw_pressure);
166 
167 /**
168  * topology_update_hw_pressure() - Update HW pressure for CPUs
169  * @cpus        : The related CPUs for which capacity has been reduced
170  * @capped_freq : The maximum allowed frequency that CPUs can run at
171  *
172  * Update the value of HW pressure for all @cpus in the mask. The
173  * cpumask should include all (online+offline) affected CPUs, to avoid
174  * operating on stale data when hot-plug is used for some CPUs. The
175  * @capped_freq reflects the currently allowed max CPUs frequency due to
176  * HW capping. It might be also a boost frequency value, which is bigger
177  * than the internal 'capacity_freq_ref' max frequency. In such case the
178  * pressure value should simply be removed, since this is an indication that
179  * there is no HW throttling. The @capped_freq must be provided in kHz.
180  */
topology_update_hw_pressure(const struct cpumask * cpus,unsigned long capped_freq)181 void topology_update_hw_pressure(const struct cpumask *cpus,
182 				      unsigned long capped_freq)
183 {
184 	unsigned long max_capacity, capacity, pressure;
185 	u32 max_freq;
186 	int cpu;
187 
188 	cpu = cpumask_first(cpus);
189 	max_capacity = arch_scale_cpu_capacity(cpu);
190 	max_freq = arch_scale_freq_ref(cpu);
191 
192 	/*
193 	 * Handle properly the boost frequencies, which should simply clean
194 	 * the HW pressure value.
195 	 */
196 	if (max_freq <= capped_freq)
197 		capacity = max_capacity;
198 	else
199 		capacity = mult_frac(max_capacity, capped_freq, max_freq);
200 
201 	pressure = max_capacity - capacity;
202 
203 	trace_hw_pressure_update(cpu, pressure);
204 
205 	for_each_cpu(cpu, cpus)
206 		WRITE_ONCE(per_cpu(hw_pressure, cpu), pressure);
207 }
208 EXPORT_SYMBOL_GPL(topology_update_hw_pressure);
209 
cpu_capacity_show(struct device * dev,struct device_attribute * attr,char * buf)210 static ssize_t cpu_capacity_show(struct device *dev,
211 				 struct device_attribute *attr,
212 				 char *buf)
213 {
214 	struct cpu *cpu = container_of(dev, struct cpu, dev);
215 
216 	return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
217 }
218 
219 static void update_topology_flags_workfn(struct work_struct *work);
220 static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
221 
222 static DEVICE_ATTR_RO(cpu_capacity);
223 
cpu_capacity_sysctl_add(unsigned int cpu)224 static int cpu_capacity_sysctl_add(unsigned int cpu)
225 {
226 	struct device *cpu_dev = get_cpu_device(cpu);
227 
228 	if (!cpu_dev)
229 		return -ENOENT;
230 
231 	device_create_file(cpu_dev, &dev_attr_cpu_capacity);
232 
233 	return 0;
234 }
235 
cpu_capacity_sysctl_remove(unsigned int cpu)236 static int cpu_capacity_sysctl_remove(unsigned int cpu)
237 {
238 	struct device *cpu_dev = get_cpu_device(cpu);
239 
240 	if (!cpu_dev)
241 		return -ENOENT;
242 
243 	device_remove_file(cpu_dev, &dev_attr_cpu_capacity);
244 
245 	return 0;
246 }
247 
register_cpu_capacity_sysctl(void)248 static int register_cpu_capacity_sysctl(void)
249 {
250 	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "topology/cpu-capacity",
251 			  cpu_capacity_sysctl_add, cpu_capacity_sysctl_remove);
252 
253 	return 0;
254 }
255 subsys_initcall(register_cpu_capacity_sysctl);
256 
257 static int update_topology;
258 
topology_update_cpu_topology(void)259 int topology_update_cpu_topology(void)
260 {
261 	return update_topology;
262 }
263 
264 /*
265  * Updating the sched_domains can't be done directly from cpufreq callbacks
266  * due to locking, so queue the work for later.
267  */
update_topology_flags_workfn(struct work_struct * work)268 static void update_topology_flags_workfn(struct work_struct *work)
269 {
270 	update_topology = 1;
271 	rebuild_sched_domains();
272 	pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
273 	update_topology = 0;
274 }
275 
276 static u32 *raw_capacity;
277 
free_raw_capacity(void)278 static int free_raw_capacity(void)
279 {
280 	kfree(raw_capacity);
281 	raw_capacity = NULL;
282 
283 	return 0;
284 }
285 
topology_normalize_cpu_scale(void)286 void topology_normalize_cpu_scale(void)
287 {
288 	u64 capacity;
289 	u64 capacity_scale;
290 	int cpu;
291 
292 	if (!raw_capacity)
293 		return;
294 
295 	capacity_scale = 1;
296 	for_each_possible_cpu(cpu) {
297 		capacity = raw_capacity[cpu] *
298 			   (per_cpu(capacity_freq_ref, cpu) ?: 1);
299 		capacity_scale = max(capacity, capacity_scale);
300 	}
301 
302 	pr_debug("cpu_capacity: capacity_scale=%llu\n", capacity_scale);
303 	for_each_possible_cpu(cpu) {
304 		capacity = raw_capacity[cpu] *
305 			   (per_cpu(capacity_freq_ref, cpu) ?: 1);
306 		capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT,
307 			capacity_scale);
308 		topology_set_cpu_scale(cpu, capacity);
309 		pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
310 			cpu, topology_get_cpu_scale(cpu));
311 	}
312 }
313 
topology_parse_cpu_capacity(struct device_node * cpu_node,int cpu)314 bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
315 {
316 	struct clk *cpu_clk;
317 	static bool cap_parsing_failed;
318 	int ret;
319 	u32 cpu_capacity;
320 
321 	if (cap_parsing_failed)
322 		return false;
323 
324 	ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
325 				   &cpu_capacity);
326 	if (!ret) {
327 		if (!raw_capacity) {
328 			raw_capacity = kcalloc(num_possible_cpus(),
329 					       sizeof(*raw_capacity),
330 					       GFP_KERNEL);
331 			if (!raw_capacity) {
332 				cap_parsing_failed = true;
333 				return false;
334 			}
335 		}
336 		raw_capacity[cpu] = cpu_capacity;
337 		pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
338 			cpu_node, raw_capacity[cpu]);
339 
340 		/*
341 		 * Update capacity_freq_ref for calculating early boot CPU capacities.
342 		 * For non-clk CPU DVFS mechanism, there's no way to get the
343 		 * frequency value now, assuming they are running at the same
344 		 * frequency (by keeping the initial capacity_freq_ref value).
345 		 */
346 		cpu_clk = of_clk_get(cpu_node, 0);
347 		if (!PTR_ERR_OR_ZERO(cpu_clk)) {
348 			per_cpu(capacity_freq_ref, cpu) =
349 				clk_get_rate(cpu_clk) / HZ_PER_KHZ;
350 			clk_put(cpu_clk);
351 		}
352 	} else {
353 		if (raw_capacity) {
354 			pr_err("cpu_capacity: missing %pOF raw capacity\n",
355 				cpu_node);
356 			pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
357 		}
358 		cap_parsing_failed = true;
359 		free_raw_capacity();
360 	}
361 
362 	return !ret;
363 }
364 
freq_inv_set_max_ratio(int cpu,u64 max_rate)365 void __weak freq_inv_set_max_ratio(int cpu, u64 max_rate)
366 {
367 }
368 
369 #ifdef CONFIG_ACPI_CPPC_LIB
370 #include <acpi/cppc_acpi.h>
371 
topology_init_cpu_capacity_cppc(void)372 static inline void topology_init_cpu_capacity_cppc(void)
373 {
374 	u64 capacity, capacity_scale = 0;
375 	struct cppc_perf_caps perf_caps;
376 	int cpu;
377 
378 	if (likely(!acpi_cpc_valid()))
379 		return;
380 
381 	raw_capacity = kcalloc(num_possible_cpus(), sizeof(*raw_capacity),
382 			       GFP_KERNEL);
383 	if (!raw_capacity)
384 		return;
385 
386 	for_each_possible_cpu(cpu) {
387 		if (!cppc_get_perf_caps(cpu, &perf_caps) &&
388 		    (perf_caps.highest_perf >= perf_caps.nominal_perf) &&
389 		    (perf_caps.highest_perf >= perf_caps.lowest_perf)) {
390 			raw_capacity[cpu] = perf_caps.highest_perf;
391 			capacity_scale = max_t(u64, capacity_scale, raw_capacity[cpu]);
392 
393 			per_cpu(capacity_freq_ref, cpu) = cppc_perf_to_khz(&perf_caps, raw_capacity[cpu]);
394 
395 			pr_debug("cpu_capacity: CPU%d cpu_capacity=%u (raw).\n",
396 				 cpu, raw_capacity[cpu]);
397 			continue;
398 		}
399 
400 		pr_err("cpu_capacity: CPU%d missing/invalid highest performance.\n", cpu);
401 		pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
402 		goto exit;
403 	}
404 
405 	for_each_possible_cpu(cpu) {
406 		freq_inv_set_max_ratio(cpu,
407 				       per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ);
408 
409 		capacity = raw_capacity[cpu];
410 		capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT,
411 				     capacity_scale);
412 		topology_set_cpu_scale(cpu, capacity);
413 		pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
414 			cpu, topology_get_cpu_scale(cpu));
415 	}
416 
417 	schedule_work(&update_topology_flags_work);
418 	pr_debug("cpu_capacity: cpu_capacity initialization done\n");
419 
420 exit:
421 	free_raw_capacity();
422 }
acpi_processor_init_invariance_cppc(void)423 void acpi_processor_init_invariance_cppc(void)
424 {
425 	topology_init_cpu_capacity_cppc();
426 }
427 #endif
428 
429 #ifdef CONFIG_CPU_FREQ
430 static cpumask_var_t cpus_to_visit;
431 static void parsing_done_workfn(struct work_struct *work);
432 static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
433 
434 static int
init_cpu_capacity_callback(struct notifier_block * nb,unsigned long val,void * data)435 init_cpu_capacity_callback(struct notifier_block *nb,
436 			   unsigned long val,
437 			   void *data)
438 {
439 	struct cpufreq_policy *policy = data;
440 	int cpu;
441 
442 	if (val != CPUFREQ_CREATE_POLICY)
443 		return 0;
444 
445 	pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
446 		 cpumask_pr_args(policy->related_cpus),
447 		 cpumask_pr_args(cpus_to_visit));
448 
449 	cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
450 
451 	for_each_cpu(cpu, policy->related_cpus) {
452 		per_cpu(capacity_freq_ref, cpu) = policy->cpuinfo.max_freq;
453 		freq_inv_set_max_ratio(cpu,
454 				       per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ);
455 	}
456 
457 	if (cpumask_empty(cpus_to_visit)) {
458 		if (raw_capacity) {
459 			topology_normalize_cpu_scale();
460 			schedule_work(&update_topology_flags_work);
461 			free_raw_capacity();
462 		}
463 		pr_debug("cpu_capacity: parsing done\n");
464 		schedule_work(&parsing_done_work);
465 	}
466 
467 	return 0;
468 }
469 
470 static struct notifier_block init_cpu_capacity_notifier = {
471 	.notifier_call = init_cpu_capacity_callback,
472 };
473 
register_cpufreq_notifier(void)474 static int __init register_cpufreq_notifier(void)
475 {
476 	int ret;
477 
478 	/*
479 	 * On ACPI-based systems skip registering cpufreq notifier as cpufreq
480 	 * information is not needed for cpu capacity initialization.
481 	 */
482 	if (!acpi_disabled)
483 		return -EINVAL;
484 
485 	if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL))
486 		return -ENOMEM;
487 
488 	cpumask_copy(cpus_to_visit, cpu_possible_mask);
489 
490 	ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
491 					CPUFREQ_POLICY_NOTIFIER);
492 
493 	if (ret)
494 		free_cpumask_var(cpus_to_visit);
495 
496 	return ret;
497 }
498 core_initcall(register_cpufreq_notifier);
499 
parsing_done_workfn(struct work_struct * work)500 static void parsing_done_workfn(struct work_struct *work)
501 {
502 	cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
503 					 CPUFREQ_POLICY_NOTIFIER);
504 	free_cpumask_var(cpus_to_visit);
505 }
506 
507 #else
508 core_initcall(free_raw_capacity);
509 #endif
510 
511 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
512 
513 /* Used to enable the SMT control */
514 static unsigned int max_smt_thread_num = 1;
515 
516 /*
517  * This function returns the logic cpu number of the node.
518  * There are basically three kinds of return values:
519  * (1) logic cpu number which is > 0.
520  * (2) -ENODEV when the device tree(DT) node is valid and found in the DT but
521  * there is no possible logical CPU in the kernel to match. This happens
522  * when CONFIG_NR_CPUS is configure to be smaller than the number of
523  * CPU nodes in DT. We need to just ignore this case.
524  * (3) -1 if the node does not exist in the device tree
525  */
get_cpu_for_node(struct device_node * node)526 static int __init get_cpu_for_node(struct device_node *node)
527 {
528 	int cpu;
529 	struct device_node *cpu_node __free(device_node) =
530 		of_parse_phandle(node, "cpu", 0);
531 
532 	if (!cpu_node)
533 		return -1;
534 
535 	cpu = of_cpu_node_to_id(cpu_node);
536 	if (cpu >= 0)
537 		topology_parse_cpu_capacity(cpu_node, cpu);
538 	else
539 		pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n",
540 			cpu_node, cpumask_pr_args(cpu_possible_mask));
541 
542 	return cpu;
543 }
544 
parse_core(struct device_node * core,int package_id,int cluster_id,int core_id)545 static int __init parse_core(struct device_node *core, int package_id,
546 			     int cluster_id, int core_id)
547 {
548 	char name[20];
549 	bool leaf = true;
550 	int i = 0;
551 	int cpu;
552 
553 	do {
554 		snprintf(name, sizeof(name), "thread%d", i);
555 		struct device_node *t __free(device_node) =
556 			of_get_child_by_name(core, name);
557 
558 		if (!t)
559 			break;
560 
561 		leaf = false;
562 		cpu = get_cpu_for_node(t);
563 		if (cpu >= 0) {
564 			cpu_topology[cpu].package_id = package_id;
565 			cpu_topology[cpu].cluster_id = cluster_id;
566 			cpu_topology[cpu].core_id = core_id;
567 			cpu_topology[cpu].thread_id = i;
568 		} else if (cpu != -ENODEV) {
569 			pr_err("%pOF: Can't get CPU for thread\n", t);
570 			return -EINVAL;
571 		}
572 		i++;
573 	} while (1);
574 
575 	max_smt_thread_num = max_t(unsigned int, max_smt_thread_num, i);
576 
577 	cpu = get_cpu_for_node(core);
578 	if (cpu >= 0) {
579 		if (!leaf) {
580 			pr_err("%pOF: Core has both threads and CPU\n",
581 			       core);
582 			return -EINVAL;
583 		}
584 
585 		cpu_topology[cpu].package_id = package_id;
586 		cpu_topology[cpu].cluster_id = cluster_id;
587 		cpu_topology[cpu].core_id = core_id;
588 	} else if (leaf && cpu != -ENODEV) {
589 		pr_err("%pOF: Can't get CPU for leaf core\n", core);
590 		return -EINVAL;
591 	}
592 
593 	return 0;
594 }
595 
parse_cluster(struct device_node * cluster,int package_id,int cluster_id,int depth)596 static int __init parse_cluster(struct device_node *cluster, int package_id,
597 				int cluster_id, int depth)
598 {
599 	char name[20];
600 	bool leaf = true;
601 	bool has_cores = false;
602 	int core_id = 0;
603 	int i, ret;
604 
605 	/*
606 	 * First check for child clusters; we currently ignore any
607 	 * information about the nesting of clusters and present the
608 	 * scheduler with a flat list of them.
609 	 */
610 	i = 0;
611 	do {
612 		snprintf(name, sizeof(name), "cluster%d", i);
613 		struct device_node *c __free(device_node) =
614 			of_get_child_by_name(cluster, name);
615 
616 		if (!c)
617 			break;
618 
619 		leaf = false;
620 		ret = parse_cluster(c, package_id, i, depth + 1);
621 		if (depth > 0)
622 			pr_warn("Topology for clusters of clusters not yet supported\n");
623 		if (ret != 0)
624 			return ret;
625 		i++;
626 	} while (1);
627 
628 	/* Now check for cores */
629 	i = 0;
630 	do {
631 		snprintf(name, sizeof(name), "core%d", i);
632 		struct device_node *c __free(device_node) =
633 			of_get_child_by_name(cluster, name);
634 
635 		if (!c)
636 			break;
637 
638 		has_cores = true;
639 
640 		if (depth == 0) {
641 			pr_err("%pOF: cpu-map children should be clusters\n", c);
642 			return -EINVAL;
643 		}
644 
645 		if (leaf) {
646 			ret = parse_core(c, package_id, cluster_id, core_id++);
647 			if (ret != 0)
648 				return ret;
649 		} else {
650 			pr_err("%pOF: Non-leaf cluster with core %s\n",
651 			       cluster, name);
652 			return -EINVAL;
653 		}
654 
655 		i++;
656 	} while (1);
657 
658 	if (leaf && !has_cores)
659 		pr_warn("%pOF: empty cluster\n", cluster);
660 
661 	return 0;
662 }
663 
parse_socket(struct device_node * socket)664 static int __init parse_socket(struct device_node *socket)
665 {
666 	char name[20];
667 	bool has_socket = false;
668 	int package_id = 0, ret;
669 
670 	do {
671 		snprintf(name, sizeof(name), "socket%d", package_id);
672 		struct device_node *c __free(device_node) =
673 			of_get_child_by_name(socket, name);
674 
675 		if (!c)
676 			break;
677 
678 		has_socket = true;
679 		ret = parse_cluster(c, package_id, -1, 0);
680 		if (ret != 0)
681 			return ret;
682 
683 		package_id++;
684 	} while (1);
685 
686 	if (!has_socket)
687 		ret = parse_cluster(socket, 0, -1, 0);
688 
689 	/*
690 	 * Reset the max_smt_thread_num to 1 on failure. Since on failure
691 	 * we need to notify the framework the SMT is not supported, but
692 	 * max_smt_thread_num can be initialized to the SMT thread number
693 	 * of the cores which are successfully parsed.
694 	 */
695 	if (ret)
696 		max_smt_thread_num = 1;
697 
698 	cpu_smt_set_num_threads(max_smt_thread_num, max_smt_thread_num);
699 
700 	return ret;
701 }
702 
parse_dt_topology(void)703 static int __init parse_dt_topology(void)
704 {
705 	int ret = 0;
706 	int cpu;
707 	struct device_node *cn __free(device_node) =
708 		of_find_node_by_path("/cpus");
709 
710 	if (!cn) {
711 		pr_err("No CPU information found in DT\n");
712 		return 0;
713 	}
714 
715 	/*
716 	 * When topology is provided cpu-map is essentially a root
717 	 * cluster with restricted subnodes.
718 	 */
719 	struct device_node *map __free(device_node) =
720 		of_get_child_by_name(cn, "cpu-map");
721 
722 	if (!map)
723 		return ret;
724 
725 	ret = parse_socket(map);
726 	if (ret != 0)
727 		return ret;
728 
729 	topology_normalize_cpu_scale();
730 
731 	/*
732 	 * Check that all cores are in the topology; the SMP code will
733 	 * only mark cores described in the DT as possible.
734 	 */
735 	for_each_possible_cpu(cpu)
736 		if (cpu_topology[cpu].package_id < 0) {
737 			return -EINVAL;
738 		}
739 
740 	return ret;
741 }
742 #endif
743 
744 /*
745  * cpu topology table
746  */
747 struct cpu_topology cpu_topology[NR_CPUS];
748 EXPORT_SYMBOL_GPL(cpu_topology);
749 
cpu_coregroup_mask(int cpu)750 const struct cpumask *cpu_coregroup_mask(int cpu)
751 {
752 	const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));
753 
754 	/* Find the smaller of NUMA, core or LLC siblings */
755 	if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
756 		/* not numa in package, lets use the package siblings */
757 		core_mask = &cpu_topology[cpu].core_sibling;
758 	}
759 
760 	if (last_level_cache_is_valid(cpu)) {
761 		if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
762 			core_mask = &cpu_topology[cpu].llc_sibling;
763 	}
764 
765 	/*
766 	 * For systems with no shared cpu-side LLC but with clusters defined,
767 	 * extend core_mask to cluster_siblings. The sched domain builder will
768 	 * then remove MC as redundant with CLS if SCHED_CLUSTER is enabled.
769 	 */
770 	if (IS_ENABLED(CONFIG_SCHED_CLUSTER) &&
771 	    cpumask_subset(core_mask, &cpu_topology[cpu].cluster_sibling))
772 		core_mask = &cpu_topology[cpu].cluster_sibling;
773 
774 	return core_mask;
775 }
776 
cpu_clustergroup_mask(int cpu)777 const struct cpumask *cpu_clustergroup_mask(int cpu)
778 {
779 	/*
780 	 * Forbid cpu_clustergroup_mask() to span more or the same CPUs as
781 	 * cpu_coregroup_mask().
782 	 */
783 	if (cpumask_subset(cpu_coregroup_mask(cpu),
784 			   &cpu_topology[cpu].cluster_sibling))
785 		return topology_sibling_cpumask(cpu);
786 
787 	return &cpu_topology[cpu].cluster_sibling;
788 }
789 
update_siblings_masks(unsigned int cpuid)790 void update_siblings_masks(unsigned int cpuid)
791 {
792 	struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
793 	int cpu, ret;
794 
795 	ret = detect_cache_attributes(cpuid);
796 	if (ret && ret != -ENOENT)
797 		pr_info("Early cacheinfo allocation failed, ret = %d\n", ret);
798 
799 	/* update core and thread sibling masks */
800 	for_each_online_cpu(cpu) {
801 		cpu_topo = &cpu_topology[cpu];
802 
803 		if (last_level_cache_is_shared(cpu, cpuid)) {
804 			cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
805 			cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
806 		}
807 
808 		if (cpuid_topo->package_id != cpu_topo->package_id)
809 			continue;
810 
811 		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
812 		cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
813 
814 		if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
815 			continue;
816 
817 		if (cpuid_topo->cluster_id >= 0) {
818 			cpumask_set_cpu(cpu, &cpuid_topo->cluster_sibling);
819 			cpumask_set_cpu(cpuid, &cpu_topo->cluster_sibling);
820 		}
821 
822 		if (cpuid_topo->core_id != cpu_topo->core_id)
823 			continue;
824 
825 		cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
826 		cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
827 	}
828 }
829 
clear_cpu_topology(int cpu)830 static void clear_cpu_topology(int cpu)
831 {
832 	struct cpu_topology *cpu_topo = &cpu_topology[cpu];
833 
834 	cpumask_clear(&cpu_topo->llc_sibling);
835 	cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);
836 
837 	cpumask_clear(&cpu_topo->cluster_sibling);
838 	cpumask_set_cpu(cpu, &cpu_topo->cluster_sibling);
839 
840 	cpumask_clear(&cpu_topo->core_sibling);
841 	cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
842 	cpumask_clear(&cpu_topo->thread_sibling);
843 	cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
844 }
845 
reset_cpu_topology(void)846 void __init reset_cpu_topology(void)
847 {
848 	unsigned int cpu;
849 
850 	for_each_possible_cpu(cpu) {
851 		struct cpu_topology *cpu_topo = &cpu_topology[cpu];
852 
853 		cpu_topo->thread_id = -1;
854 		cpu_topo->core_id = -1;
855 		cpu_topo->cluster_id = -1;
856 		cpu_topo->package_id = -1;
857 
858 		clear_cpu_topology(cpu);
859 	}
860 }
861 
remove_cpu_topology(unsigned int cpu)862 void remove_cpu_topology(unsigned int cpu)
863 {
864 	int sibling;
865 
866 	for_each_cpu(sibling, topology_core_cpumask(cpu))
867 		cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
868 	for_each_cpu(sibling, topology_sibling_cpumask(cpu))
869 		cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
870 	for_each_cpu(sibling, topology_cluster_cpumask(cpu))
871 		cpumask_clear_cpu(cpu, topology_cluster_cpumask(sibling));
872 	for_each_cpu(sibling, topology_llc_cpumask(cpu))
873 		cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));
874 
875 	clear_cpu_topology(cpu);
876 }
877 
parse_acpi_topology(void)878 __weak int __init parse_acpi_topology(void)
879 {
880 	return 0;
881 }
882 
883 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
init_cpu_topology(void)884 void __init init_cpu_topology(void)
885 {
886 	int cpu, ret;
887 
888 	reset_cpu_topology();
889 	ret = parse_acpi_topology();
890 	if (!ret)
891 		ret = of_have_populated_dt() && parse_dt_topology();
892 
893 	if (ret) {
894 		/*
895 		 * Discard anything that was parsed if we hit an error so we
896 		 * don't use partial information. But do not return yet to give
897 		 * arch-specific early cache level detection a chance to run.
898 		 */
899 		reset_cpu_topology();
900 	}
901 
902 	for_each_possible_cpu(cpu) {
903 		ret = fetch_cache_info(cpu);
904 		if (!ret)
905 			continue;
906 		else if (ret != -ENOENT)
907 			pr_err("Early cacheinfo failed, ret = %d\n", ret);
908 		return;
909 	}
910 }
911 
store_cpu_topology(unsigned int cpuid)912 void store_cpu_topology(unsigned int cpuid)
913 {
914 	struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
915 
916 	if (cpuid_topo->package_id != -1)
917 		goto topology_populated;
918 
919 	cpuid_topo->thread_id = -1;
920 	cpuid_topo->core_id = cpuid;
921 	cpuid_topo->package_id = cpu_to_node(cpuid);
922 
923 	pr_debug("CPU%u: package %d core %d thread %d\n",
924 		 cpuid, cpuid_topo->package_id, cpuid_topo->core_id,
925 		 cpuid_topo->thread_id);
926 
927 topology_populated:
928 	update_siblings_masks(cpuid);
929 }
930 #endif
931