// 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/cpu.h> #include <linux/cpufreq.h> #include <linux/device.h> #include <linux/of.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/sched/topology.h> #include <linux/cpuset.h> #include <linux/cpumask.h> #include <linux/init.h> #include <linux/percpu.h> #include <linux/sched.h> #include <linux/smp.h> DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE; void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, unsigned long max_freq) { unsigned long scale; int i; scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq; for_each_cpu(i, cpus) per_cpu(freq_scale, i) = scale; } DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE; void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity) { per_cpu(cpu_scale, cpu) = capacity; } 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 sprintf(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 register_cpu_capacity_sysctl(void) { int i; struct device *cpu; for_each_possible_cpu(i) { cpu = get_cpu_device(i); if (!cpu) { pr_err("%s: too early to get CPU%d device!\n", __func__, i); continue; } device_create_file(cpu, &dev_attr_cpu_capacity); } 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 capacity_scale; 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; int cpu; if (!raw_capacity) return; pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale); for_each_possible_cpu(cpu) { pr_debug("cpu_capacity: cpu=%d raw_capacity=%u\n", cpu, raw_capacity[cpu]); capacity = (raw_capacity[cpu] << 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) { 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; } } capacity_scale = max(cpu_capacity, capacity_scale); raw_capacity[cpu] = cpu_capacity; pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n", cpu_node, raw_capacity[cpu]); } 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; } #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 (!raw_capacity) return 0; 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) { raw_capacity[cpu] = topology_get_cpu_scale(cpu) * policy->cpuinfo.max_freq / 1000UL; capacity_scale = max(raw_capacity[cpu], capacity_scale); } if (cpumask_empty(cpus_to_visit)) { 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 we need to use the default cpu capacity * until we have the necessary code to parse the cpu capacity, so * skip registering cpufreq notifier. */ if (!acpi_disabled || !raw_capacity) 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) { struct device_node *cpu_node; int cpu; cpu_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)); of_node_put(cpu_node); return cpu; } static int __init parse_core(struct device_node *core, int package_id, int core_id) { char name[10]; bool leaf = true; int i = 0; int cpu; struct device_node *t; do { snprintf(name, sizeof(name), "thread%d", i); t = of_get_child_by_name(core, name); if (t) { leaf = false; cpu = get_cpu_for_node(t); if (cpu >= 0) { cpu_topology[cpu].package_id = package_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); of_node_put(t); return -EINVAL; } of_node_put(t); } i++; } while (t); 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].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 depth) { char name[10]; bool leaf = true; bool has_cores = false; struct device_node *c; static int package_id __initdata; 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); c = of_get_child_by_name(cluster, name); if (c) { leaf = false; ret = parse_cluster(c, depth + 1); of_node_put(c); if (ret != 0) return ret; } i++; } while (c); /* Now check for cores */ i = 0; do { snprintf(name, sizeof(name), "core%d", i); c = of_get_child_by_name(cluster, name); if (c) { has_cores = true; if (depth == 0) { pr_err("%pOF: cpu-map children should be clusters\n", c); of_node_put(c); return -EINVAL; } if (leaf) { ret = parse_core(c, package_id, core_id++); } else { pr_err("%pOF: Non-leaf cluster with core %s\n", cluster, name); ret = -EINVAL; } of_node_put(c); if (ret != 0) return ret; } i++; } while (c); if (leaf && !has_cores) pr_warn("%pOF: empty cluster\n", cluster); if (leaf) package_id++; return 0; } static int __init parse_dt_topology(void) { struct device_node *cn, *map; int ret = 0; int cpu; cn = 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. */ map = of_get_child_by_name(cn, "cpu-map"); if (!map) goto out; ret = parse_cluster(map, 0); if (ret != 0) goto out_map; 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 == -1) ret = -EINVAL; out_map: of_node_put(map); out: of_node_put(cn); 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 (cpu_topology[cpu].llc_id != -1) { if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask)) core_mask = &cpu_topology[cpu].llc_sibling; } return core_mask; } void update_siblings_masks(unsigned int cpuid) { struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid]; int cpu; /* update core and thread sibling masks */ for_each_online_cpu(cpu) { cpu_topo = &cpu_topology[cpu]; if (cpuid_topo->llc_id == cpu_topo->llc_id) { 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->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->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->package_id = -1; cpu_topo->llc_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_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) { reset_cpu_topology(); /* * Discard anything that was parsed if we hit an error so we * don't use partial information. */ if (parse_acpi_topology()) reset_cpu_topology(); else if (of_have_populated_dt() && parse_dt_topology()) reset_cpu_topology(); } #endif