1 // SPDX-License-Identifier: GPL-2.0
3 * Arch specific cpu topology information
5 * Copyright (C) 2016, ARM Ltd.
6 * Written by: Juri Lelli, ARM Ltd.
9 #include <linux/acpi.h>
10 #include <linux/cacheinfo.h>
11 #include <linux/cpu.h>
12 #include <linux/cpufreq.h>
13 #include <linux/device.h>
15 #include <linux/slab.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/rcupdate.h>
21 #include <linux/sched.h>
23 #define CREATE_TRACE_POINTS
24 #include <trace/events/thermal_pressure.h>
26 static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data);
27 static struct cpumask scale_freq_counters_mask;
28 static bool scale_freq_invariant;
29 static DEFINE_PER_CPU(u32, freq_factor) = 1;
31 static bool supports_scale_freq_counters(const struct cpumask *cpus)
33 return cpumask_subset(cpus, &scale_freq_counters_mask);
36 bool topology_scale_freq_invariant(void)
38 return cpufreq_supports_freq_invariance() ||
39 supports_scale_freq_counters(cpu_online_mask);
42 static void update_scale_freq_invariant(bool status)
44 if (scale_freq_invariant == status)
48 * Task scheduler behavior depends on frequency invariance support,
49 * either cpufreq or counter driven. If the support status changes as
50 * a result of counter initialisation and use, retrigger the build of
51 * scheduling domains to ensure the information is propagated properly.
53 if (topology_scale_freq_invariant() == status) {
54 scale_freq_invariant = status;
55 rebuild_sched_domains_energy();
59 void topology_set_scale_freq_source(struct scale_freq_data *data,
60 const struct cpumask *cpus)
62 struct scale_freq_data *sfd;
66 * Avoid calling rebuild_sched_domains() unnecessarily if FIE is
67 * supported by cpufreq.
69 if (cpumask_empty(&scale_freq_counters_mask))
70 scale_freq_invariant = topology_scale_freq_invariant();
74 for_each_cpu(cpu, cpus) {
75 sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
77 /* Use ARCH provided counters whenever possible */
78 if (!sfd || sfd->source != SCALE_FREQ_SOURCE_ARCH) {
79 rcu_assign_pointer(per_cpu(sft_data, cpu), data);
80 cpumask_set_cpu(cpu, &scale_freq_counters_mask);
86 update_scale_freq_invariant(true);
88 EXPORT_SYMBOL_GPL(topology_set_scale_freq_source);
90 void topology_clear_scale_freq_source(enum scale_freq_source source,
91 const struct cpumask *cpus)
93 struct scale_freq_data *sfd;
98 for_each_cpu(cpu, cpus) {
99 sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));
101 if (sfd && sfd->source == source) {
102 rcu_assign_pointer(per_cpu(sft_data, cpu), NULL);
103 cpumask_clear_cpu(cpu, &scale_freq_counters_mask);
110 * Make sure all references to previous sft_data are dropped to avoid
111 * use-after-free races.
115 update_scale_freq_invariant(false);
117 EXPORT_SYMBOL_GPL(topology_clear_scale_freq_source);
119 void topology_scale_freq_tick(void)
121 struct scale_freq_data *sfd = rcu_dereference_sched(*this_cpu_ptr(&sft_data));
124 sfd->set_freq_scale();
127 DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
128 EXPORT_PER_CPU_SYMBOL_GPL(arch_freq_scale);
130 void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq,
131 unsigned long max_freq)
136 if (WARN_ON_ONCE(!cur_freq || !max_freq))
140 * If the use of counters for FIE is enabled, just return as we don't
141 * want to update the scale factor with information from CPUFREQ.
142 * Instead the scale factor will be updated from arch_scale_freq_tick.
144 if (supports_scale_freq_counters(cpus))
147 scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;
149 for_each_cpu(i, cpus)
150 per_cpu(arch_freq_scale, i) = scale;
153 DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
154 EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);
156 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
158 per_cpu(cpu_scale, cpu) = capacity;
161 DEFINE_PER_CPU(unsigned long, thermal_pressure);
164 * topology_update_thermal_pressure() - Update thermal pressure for CPUs
165 * @cpus : The related CPUs for which capacity has been reduced
166 * @capped_freq : The maximum allowed frequency that CPUs can run at
168 * Update the value of thermal pressure for all @cpus in the mask. The
169 * cpumask should include all (online+offline) affected CPUs, to avoid
170 * operating on stale data when hot-plug is used for some CPUs. The
171 * @capped_freq reflects the currently allowed max CPUs frequency due to
172 * thermal capping. It might be also a boost frequency value, which is bigger
173 * than the internal 'freq_factor' max frequency. In such case the pressure
174 * value should simply be removed, since this is an indication that there is
175 * no thermal throttling. The @capped_freq must be provided in kHz.
177 void topology_update_thermal_pressure(const struct cpumask *cpus,
178 unsigned long capped_freq)
180 unsigned long max_capacity, capacity, th_pressure;
184 cpu = cpumask_first(cpus);
185 max_capacity = arch_scale_cpu_capacity(cpu);
186 max_freq = per_cpu(freq_factor, cpu);
188 /* Convert to MHz scale which is used in 'freq_factor' */
192 * Handle properly the boost frequencies, which should simply clean
193 * the thermal pressure value.
195 if (max_freq <= capped_freq)
196 capacity = max_capacity;
198 capacity = mult_frac(max_capacity, capped_freq, max_freq);
200 th_pressure = max_capacity - capacity;
202 trace_thermal_pressure_update(cpu, th_pressure);
204 for_each_cpu(cpu, cpus)
205 WRITE_ONCE(per_cpu(thermal_pressure, cpu), th_pressure);
207 EXPORT_SYMBOL_GPL(topology_update_thermal_pressure);
209 static ssize_t cpu_capacity_show(struct device *dev,
210 struct device_attribute *attr,
213 struct cpu *cpu = container_of(dev, struct cpu, dev);
215 return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
218 static void update_topology_flags_workfn(struct work_struct *work);
219 static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
221 static DEVICE_ATTR_RO(cpu_capacity);
223 static int register_cpu_capacity_sysctl(void)
228 for_each_possible_cpu(i) {
229 cpu = get_cpu_device(i);
231 pr_err("%s: too early to get CPU%d device!\n",
235 device_create_file(cpu, &dev_attr_cpu_capacity);
240 subsys_initcall(register_cpu_capacity_sysctl);
242 static int update_topology;
244 int topology_update_cpu_topology(void)
246 return update_topology;
250 * Updating the sched_domains can't be done directly from cpufreq callbacks
251 * due to locking, so queue the work for later.
253 static void update_topology_flags_workfn(struct work_struct *work)
256 rebuild_sched_domains();
257 pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
261 static u32 *raw_capacity;
263 static int free_raw_capacity(void)
271 void topology_normalize_cpu_scale(void)
281 for_each_possible_cpu(cpu) {
282 capacity = raw_capacity[cpu] * per_cpu(freq_factor, cpu);
283 capacity_scale = max(capacity, capacity_scale);
286 pr_debug("cpu_capacity: capacity_scale=%llu\n", capacity_scale);
287 for_each_possible_cpu(cpu) {
288 capacity = raw_capacity[cpu] * per_cpu(freq_factor, cpu);
289 capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT,
291 topology_set_cpu_scale(cpu, capacity);
292 pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
293 cpu, topology_get_cpu_scale(cpu));
297 bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
300 static bool cap_parsing_failed;
304 if (cap_parsing_failed)
307 ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
311 raw_capacity = kcalloc(num_possible_cpus(),
312 sizeof(*raw_capacity),
315 cap_parsing_failed = true;
319 raw_capacity[cpu] = cpu_capacity;
320 pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
321 cpu_node, raw_capacity[cpu]);
324 * Update freq_factor for calculating early boot cpu capacities.
325 * For non-clk CPU DVFS mechanism, there's no way to get the
326 * frequency value now, assuming they are running at the same
327 * frequency (by keeping the initial freq_factor value).
329 cpu_clk = of_clk_get(cpu_node, 0);
330 if (!PTR_ERR_OR_ZERO(cpu_clk)) {
331 per_cpu(freq_factor, cpu) =
332 clk_get_rate(cpu_clk) / 1000;
337 pr_err("cpu_capacity: missing %pOF raw capacity\n",
339 pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
341 cap_parsing_failed = true;
348 #ifdef CONFIG_ACPI_CPPC_LIB
349 #include <acpi/cppc_acpi.h>
351 void topology_init_cpu_capacity_cppc(void)
353 struct cppc_perf_caps perf_caps;
356 if (likely(!acpi_cpc_valid()))
359 raw_capacity = kcalloc(num_possible_cpus(), sizeof(*raw_capacity),
364 for_each_possible_cpu(cpu) {
365 if (!cppc_get_perf_caps(cpu, &perf_caps) &&
366 (perf_caps.highest_perf >= perf_caps.nominal_perf) &&
367 (perf_caps.highest_perf >= perf_caps.lowest_perf)) {
368 raw_capacity[cpu] = perf_caps.highest_perf;
369 pr_debug("cpu_capacity: CPU%d cpu_capacity=%u (raw).\n",
370 cpu, raw_capacity[cpu]);
374 pr_err("cpu_capacity: CPU%d missing/invalid highest performance.\n", cpu);
375 pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
379 topology_normalize_cpu_scale();
380 schedule_work(&update_topology_flags_work);
381 pr_debug("cpu_capacity: cpu_capacity initialization done\n");
388 #ifdef CONFIG_CPU_FREQ
389 static cpumask_var_t cpus_to_visit;
390 static void parsing_done_workfn(struct work_struct *work);
391 static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
394 init_cpu_capacity_callback(struct notifier_block *nb,
398 struct cpufreq_policy *policy = data;
404 if (val != CPUFREQ_CREATE_POLICY)
407 pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
408 cpumask_pr_args(policy->related_cpus),
409 cpumask_pr_args(cpus_to_visit));
411 cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
413 for_each_cpu(cpu, policy->related_cpus)
414 per_cpu(freq_factor, cpu) = policy->cpuinfo.max_freq / 1000;
416 if (cpumask_empty(cpus_to_visit)) {
417 topology_normalize_cpu_scale();
418 schedule_work(&update_topology_flags_work);
420 pr_debug("cpu_capacity: parsing done\n");
421 schedule_work(&parsing_done_work);
427 static struct notifier_block init_cpu_capacity_notifier = {
428 .notifier_call = init_cpu_capacity_callback,
431 static int __init register_cpufreq_notifier(void)
436 * On ACPI-based systems skip registering cpufreq notifier as cpufreq
437 * information is not needed for cpu capacity initialization.
439 if (!acpi_disabled || !raw_capacity)
442 if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL))
445 cpumask_copy(cpus_to_visit, cpu_possible_mask);
447 ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
448 CPUFREQ_POLICY_NOTIFIER);
451 free_cpumask_var(cpus_to_visit);
455 core_initcall(register_cpufreq_notifier);
457 static void parsing_done_workfn(struct work_struct *work)
459 cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
460 CPUFREQ_POLICY_NOTIFIER);
461 free_cpumask_var(cpus_to_visit);
465 core_initcall(free_raw_capacity);
468 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
470 * This function returns the logic cpu number of the node.
471 * There are basically three kinds of return values:
472 * (1) logic cpu number which is > 0.
473 * (2) -ENODEV when the device tree(DT) node is valid and found in the DT but
474 * there is no possible logical CPU in the kernel to match. This happens
475 * when CONFIG_NR_CPUS is configure to be smaller than the number of
476 * CPU nodes in DT. We need to just ignore this case.
477 * (3) -1 if the node does not exist in the device tree
479 static int __init get_cpu_for_node(struct device_node *node)
481 struct device_node *cpu_node;
484 cpu_node = of_parse_phandle(node, "cpu", 0);
488 cpu = of_cpu_node_to_id(cpu_node);
490 topology_parse_cpu_capacity(cpu_node, cpu);
492 pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n",
493 cpu_node, cpumask_pr_args(cpu_possible_mask));
495 of_node_put(cpu_node);
499 static int __init parse_core(struct device_node *core, int package_id,
500 int cluster_id, int core_id)
506 struct device_node *t;
509 snprintf(name, sizeof(name), "thread%d", i);
510 t = of_get_child_by_name(core, name);
513 cpu = get_cpu_for_node(t);
515 cpu_topology[cpu].package_id = package_id;
516 cpu_topology[cpu].cluster_id = cluster_id;
517 cpu_topology[cpu].core_id = core_id;
518 cpu_topology[cpu].thread_id = i;
519 } else if (cpu != -ENODEV) {
520 pr_err("%pOF: Can't get CPU for thread\n", t);
529 cpu = get_cpu_for_node(core);
532 pr_err("%pOF: Core has both threads and CPU\n",
537 cpu_topology[cpu].package_id = package_id;
538 cpu_topology[cpu].cluster_id = cluster_id;
539 cpu_topology[cpu].core_id = core_id;
540 } else if (leaf && cpu != -ENODEV) {
541 pr_err("%pOF: Can't get CPU for leaf core\n", core);
548 static int __init parse_cluster(struct device_node *cluster, int package_id,
549 int cluster_id, int depth)
553 bool has_cores = false;
554 struct device_node *c;
559 * First check for child clusters; we currently ignore any
560 * information about the nesting of clusters and present the
561 * scheduler with a flat list of them.
565 snprintf(name, sizeof(name), "cluster%d", i);
566 c = of_get_child_by_name(cluster, name);
569 ret = parse_cluster(c, package_id, i, depth + 1);
571 pr_warn("Topology for clusters of clusters not yet supported\n");
579 /* Now check for cores */
582 snprintf(name, sizeof(name), "core%d", i);
583 c = of_get_child_by_name(cluster, name);
588 pr_err("%pOF: cpu-map children should be clusters\n",
595 ret = parse_core(c, package_id, cluster_id,
598 pr_err("%pOF: Non-leaf cluster with core %s\n",
610 if (leaf && !has_cores)
611 pr_warn("%pOF: empty cluster\n", cluster);
616 static int __init parse_socket(struct device_node *socket)
619 struct device_node *c;
620 bool has_socket = false;
621 int package_id = 0, ret;
624 snprintf(name, sizeof(name), "socket%d", package_id);
625 c = of_get_child_by_name(socket, name);
628 ret = parse_cluster(c, package_id, -1, 0);
637 ret = parse_cluster(socket, 0, -1, 0);
642 static int __init parse_dt_topology(void)
644 struct device_node *cn, *map;
648 cn = of_find_node_by_path("/cpus");
650 pr_err("No CPU information found in DT\n");
655 * When topology is provided cpu-map is essentially a root
656 * cluster with restricted subnodes.
658 map = of_get_child_by_name(cn, "cpu-map");
662 ret = parse_socket(map);
666 topology_normalize_cpu_scale();
669 * Check that all cores are in the topology; the SMP code will
670 * only mark cores described in the DT as possible.
672 for_each_possible_cpu(cpu)
673 if (cpu_topology[cpu].package_id < 0) {
689 struct cpu_topology cpu_topology[NR_CPUS];
690 EXPORT_SYMBOL_GPL(cpu_topology);
692 const struct cpumask *cpu_coregroup_mask(int cpu)
694 const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));
696 /* Find the smaller of NUMA, core or LLC siblings */
697 if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
698 /* not numa in package, lets use the package siblings */
699 core_mask = &cpu_topology[cpu].core_sibling;
702 if (last_level_cache_is_valid(cpu)) {
703 if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
704 core_mask = &cpu_topology[cpu].llc_sibling;
708 * For systems with no shared cpu-side LLC but with clusters defined,
709 * extend core_mask to cluster_siblings. The sched domain builder will
710 * then remove MC as redundant with CLS if SCHED_CLUSTER is enabled.
712 if (IS_ENABLED(CONFIG_SCHED_CLUSTER) &&
713 cpumask_subset(core_mask, &cpu_topology[cpu].cluster_sibling))
714 core_mask = &cpu_topology[cpu].cluster_sibling;
719 const struct cpumask *cpu_clustergroup_mask(int cpu)
722 * Forbid cpu_clustergroup_mask() to span more or the same CPUs as
723 * cpu_coregroup_mask().
725 if (cpumask_subset(cpu_coregroup_mask(cpu),
726 &cpu_topology[cpu].cluster_sibling))
727 return topology_sibling_cpumask(cpu);
729 return &cpu_topology[cpu].cluster_sibling;
732 void update_siblings_masks(unsigned int cpuid)
734 struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
737 ret = detect_cache_attributes(cpuid);
738 if (ret && ret != -ENOENT)
739 pr_info("Early cacheinfo allocation failed, ret = %d\n", ret);
741 /* update core and thread sibling masks */
742 for_each_online_cpu(cpu) {
743 cpu_topo = &cpu_topology[cpu];
745 if (last_level_cache_is_shared(cpu, cpuid)) {
746 cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
747 cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
750 if (cpuid_topo->package_id != cpu_topo->package_id)
753 cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
754 cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
756 if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
759 if (cpuid_topo->cluster_id >= 0) {
760 cpumask_set_cpu(cpu, &cpuid_topo->cluster_sibling);
761 cpumask_set_cpu(cpuid, &cpu_topo->cluster_sibling);
764 if (cpuid_topo->core_id != cpu_topo->core_id)
767 cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
768 cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
772 static void clear_cpu_topology(int cpu)
774 struct cpu_topology *cpu_topo = &cpu_topology[cpu];
776 cpumask_clear(&cpu_topo->llc_sibling);
777 cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);
779 cpumask_clear(&cpu_topo->cluster_sibling);
780 cpumask_set_cpu(cpu, &cpu_topo->cluster_sibling);
782 cpumask_clear(&cpu_topo->core_sibling);
783 cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
784 cpumask_clear(&cpu_topo->thread_sibling);
785 cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
788 void __init reset_cpu_topology(void)
792 for_each_possible_cpu(cpu) {
793 struct cpu_topology *cpu_topo = &cpu_topology[cpu];
795 cpu_topo->thread_id = -1;
796 cpu_topo->core_id = -1;
797 cpu_topo->cluster_id = -1;
798 cpu_topo->package_id = -1;
800 clear_cpu_topology(cpu);
804 void remove_cpu_topology(unsigned int cpu)
808 for_each_cpu(sibling, topology_core_cpumask(cpu))
809 cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
810 for_each_cpu(sibling, topology_sibling_cpumask(cpu))
811 cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
812 for_each_cpu(sibling, topology_cluster_cpumask(cpu))
813 cpumask_clear_cpu(cpu, topology_cluster_cpumask(sibling));
814 for_each_cpu(sibling, topology_llc_cpumask(cpu))
815 cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));
817 clear_cpu_topology(cpu);
820 __weak int __init parse_acpi_topology(void)
825 #if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
826 void __init init_cpu_topology(void)
830 reset_cpu_topology();
831 ret = parse_acpi_topology();
833 ret = of_have_populated_dt() && parse_dt_topology();
837 * Discard anything that was parsed if we hit an error so we
838 * don't use partial information. But do not return yet to give
839 * arch-specific early cache level detection a chance to run.
841 reset_cpu_topology();
844 for_each_possible_cpu(cpu) {
845 ret = fetch_cache_info(cpu);
848 else if (ret != -ENOENT)
849 pr_err("Early cacheinfo failed, ret = %d\n", ret);
854 void store_cpu_topology(unsigned int cpuid)
856 struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
858 if (cpuid_topo->package_id != -1)
859 goto topology_populated;
861 cpuid_topo->thread_id = -1;
862 cpuid_topo->core_id = cpuid;
863 cpuid_topo->package_id = cpu_to_node(cpuid);
865 pr_debug("CPU%u: package %d core %d thread %d\n",
866 cpuid, cpuid_topo->package_id, cpuid_topo->core_id,
867 cpuid_topo->thread_id);
870 update_siblings_masks(cpuid);