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![Zeng Tao](/assets/img/avatar_default.png)
When the kernel is configured with CONFIG_NR_CPUS smaller than the number of CPU nodes in the device tree(DT), all the CPU nodes parsing done to fetch topology information will fail. This is not reasonable as it is legal to have all the physical CPUs in the system in the DT. Let us just skip such CPU DT nodes that are not used in the kernel rather than returning an error. Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com> Link: https://lore.kernel.org/r/1579225973-32423-1-git-send-email-prime.zeng@hisilicon.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
551 lines
12 KiB
C
551 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Arch specific cpu topology information
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*
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* Copyright (C) 2016, ARM Ltd.
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* Written by: Juri Lelli, ARM Ltd.
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*/
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#include <linux/acpi.h>
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#include <linux/cpu.h>
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#include <linux/cpufreq.h>
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#include <linux/device.h>
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#include <linux/of.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/sched/topology.h>
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#include <linux/cpuset.h>
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#include <linux/cpumask.h>
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#include <linux/init.h>
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#include <linux/percpu.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE;
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void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
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unsigned long max_freq)
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{
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unsigned long scale;
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int i;
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scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;
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for_each_cpu(i, cpus)
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per_cpu(freq_scale, i) = scale;
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}
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DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
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void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
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{
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per_cpu(cpu_scale, cpu) = capacity;
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}
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static ssize_t cpu_capacity_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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struct cpu *cpu = container_of(dev, struct cpu, dev);
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return sprintf(buf, "%lu\n", topology_get_cpu_scale(cpu->dev.id));
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}
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static void update_topology_flags_workfn(struct work_struct *work);
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static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);
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static DEVICE_ATTR_RO(cpu_capacity);
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static int register_cpu_capacity_sysctl(void)
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{
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int i;
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struct device *cpu;
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for_each_possible_cpu(i) {
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cpu = get_cpu_device(i);
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if (!cpu) {
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pr_err("%s: too early to get CPU%d device!\n",
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__func__, i);
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continue;
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}
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device_create_file(cpu, &dev_attr_cpu_capacity);
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}
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return 0;
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}
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subsys_initcall(register_cpu_capacity_sysctl);
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static int update_topology;
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int topology_update_cpu_topology(void)
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{
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return update_topology;
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}
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/*
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* Updating the sched_domains can't be done directly from cpufreq callbacks
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* due to locking, so queue the work for later.
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*/
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static void update_topology_flags_workfn(struct work_struct *work)
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{
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update_topology = 1;
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rebuild_sched_domains();
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pr_debug("sched_domain hierarchy rebuilt, flags updated\n");
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update_topology = 0;
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}
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static u32 capacity_scale;
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static u32 *raw_capacity;
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static int free_raw_capacity(void)
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{
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kfree(raw_capacity);
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raw_capacity = NULL;
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return 0;
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}
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void topology_normalize_cpu_scale(void)
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{
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u64 capacity;
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int cpu;
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if (!raw_capacity)
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return;
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pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
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for_each_possible_cpu(cpu) {
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pr_debug("cpu_capacity: cpu=%d raw_capacity=%u\n",
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cpu, raw_capacity[cpu]);
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capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT)
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/ capacity_scale;
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topology_set_cpu_scale(cpu, capacity);
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pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
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cpu, topology_get_cpu_scale(cpu));
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}
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}
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bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
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{
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static bool cap_parsing_failed;
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int ret;
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u32 cpu_capacity;
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if (cap_parsing_failed)
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return false;
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ret = of_property_read_u32(cpu_node, "capacity-dmips-mhz",
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&cpu_capacity);
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if (!ret) {
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if (!raw_capacity) {
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raw_capacity = kcalloc(num_possible_cpus(),
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sizeof(*raw_capacity),
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GFP_KERNEL);
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if (!raw_capacity) {
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cap_parsing_failed = true;
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return false;
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}
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}
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capacity_scale = max(cpu_capacity, capacity_scale);
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raw_capacity[cpu] = cpu_capacity;
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pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
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cpu_node, raw_capacity[cpu]);
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} else {
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if (raw_capacity) {
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pr_err("cpu_capacity: missing %pOF raw capacity\n",
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cpu_node);
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pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
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}
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cap_parsing_failed = true;
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free_raw_capacity();
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}
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return !ret;
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}
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#ifdef CONFIG_CPU_FREQ
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static cpumask_var_t cpus_to_visit;
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static void parsing_done_workfn(struct work_struct *work);
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static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
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static int
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init_cpu_capacity_callback(struct notifier_block *nb,
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unsigned long val,
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void *data)
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{
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struct cpufreq_policy *policy = data;
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int cpu;
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if (!raw_capacity)
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return 0;
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if (val != CPUFREQ_CREATE_POLICY)
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return 0;
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pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
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cpumask_pr_args(policy->related_cpus),
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cpumask_pr_args(cpus_to_visit));
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cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
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for_each_cpu(cpu, policy->related_cpus) {
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raw_capacity[cpu] = topology_get_cpu_scale(cpu) *
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policy->cpuinfo.max_freq / 1000UL;
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capacity_scale = max(raw_capacity[cpu], capacity_scale);
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}
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if (cpumask_empty(cpus_to_visit)) {
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topology_normalize_cpu_scale();
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schedule_work(&update_topology_flags_work);
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free_raw_capacity();
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pr_debug("cpu_capacity: parsing done\n");
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schedule_work(&parsing_done_work);
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}
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return 0;
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}
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static struct notifier_block init_cpu_capacity_notifier = {
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.notifier_call = init_cpu_capacity_callback,
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};
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static int __init register_cpufreq_notifier(void)
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{
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int ret;
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/*
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* on ACPI-based systems we need to use the default cpu capacity
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* until we have the necessary code to parse the cpu capacity, so
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* skip registering cpufreq notifier.
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*/
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if (!acpi_disabled || !raw_capacity)
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return -EINVAL;
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if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL))
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return -ENOMEM;
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cpumask_copy(cpus_to_visit, cpu_possible_mask);
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ret = cpufreq_register_notifier(&init_cpu_capacity_notifier,
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CPUFREQ_POLICY_NOTIFIER);
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if (ret)
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free_cpumask_var(cpus_to_visit);
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return ret;
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}
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core_initcall(register_cpufreq_notifier);
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static void parsing_done_workfn(struct work_struct *work)
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{
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cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
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CPUFREQ_POLICY_NOTIFIER);
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free_cpumask_var(cpus_to_visit);
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}
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#else
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core_initcall(free_raw_capacity);
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#endif
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#if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
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/*
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* This function returns the logic cpu number of the node.
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* There are basically three kinds of return values:
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* (1) logic cpu number which is > 0.
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* (2) -ENODEV when the device tree(DT) node is valid and found in the DT but
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* there is no possible logical CPU in the kernel to match. This happens
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* when CONFIG_NR_CPUS is configure to be smaller than the number of
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* CPU nodes in DT. We need to just ignore this case.
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* (3) -1 if the node does not exist in the device tree
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*/
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static int __init get_cpu_for_node(struct device_node *node)
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{
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struct device_node *cpu_node;
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int cpu;
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cpu_node = of_parse_phandle(node, "cpu", 0);
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if (!cpu_node)
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return -1;
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cpu = of_cpu_node_to_id(cpu_node);
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if (cpu >= 0)
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topology_parse_cpu_capacity(cpu_node, cpu);
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else
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pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n",
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cpu_node, cpumask_pr_args(cpu_possible_mask));
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of_node_put(cpu_node);
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return cpu;
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}
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static int __init parse_core(struct device_node *core, int package_id,
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int core_id)
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{
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char name[10];
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bool leaf = true;
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int i = 0;
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int cpu;
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struct device_node *t;
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do {
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snprintf(name, sizeof(name), "thread%d", i);
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t = of_get_child_by_name(core, name);
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if (t) {
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leaf = false;
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cpu = get_cpu_for_node(t);
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if (cpu >= 0) {
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cpu_topology[cpu].package_id = package_id;
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cpu_topology[cpu].core_id = core_id;
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cpu_topology[cpu].thread_id = i;
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} else if (cpu != -ENODEV) {
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pr_err("%pOF: Can't get CPU for thread\n", t);
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of_node_put(t);
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return -EINVAL;
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}
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of_node_put(t);
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}
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i++;
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} while (t);
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cpu = get_cpu_for_node(core);
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if (cpu >= 0) {
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if (!leaf) {
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pr_err("%pOF: Core has both threads and CPU\n",
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core);
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return -EINVAL;
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}
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cpu_topology[cpu].package_id = package_id;
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cpu_topology[cpu].core_id = core_id;
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} else if (leaf && cpu != -ENODEV) {
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pr_err("%pOF: Can't get CPU for leaf core\n", core);
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return -EINVAL;
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}
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return 0;
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}
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static int __init parse_cluster(struct device_node *cluster, int depth)
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{
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char name[10];
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bool leaf = true;
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bool has_cores = false;
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struct device_node *c;
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static int package_id __initdata;
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int core_id = 0;
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int i, ret;
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/*
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* First check for child clusters; we currently ignore any
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* information about the nesting of clusters and present the
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* scheduler with a flat list of them.
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*/
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i = 0;
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do {
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snprintf(name, sizeof(name), "cluster%d", i);
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c = of_get_child_by_name(cluster, name);
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if (c) {
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leaf = false;
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ret = parse_cluster(c, depth + 1);
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of_node_put(c);
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if (ret != 0)
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return ret;
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}
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i++;
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} while (c);
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/* Now check for cores */
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i = 0;
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do {
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snprintf(name, sizeof(name), "core%d", i);
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c = of_get_child_by_name(cluster, name);
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if (c) {
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has_cores = true;
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if (depth == 0) {
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pr_err("%pOF: cpu-map children should be clusters\n",
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c);
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of_node_put(c);
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return -EINVAL;
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}
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if (leaf) {
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ret = parse_core(c, package_id, core_id++);
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} else {
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pr_err("%pOF: Non-leaf cluster with core %s\n",
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cluster, name);
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ret = -EINVAL;
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}
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of_node_put(c);
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if (ret != 0)
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return ret;
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}
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i++;
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} while (c);
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if (leaf && !has_cores)
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pr_warn("%pOF: empty cluster\n", cluster);
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if (leaf)
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package_id++;
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return 0;
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}
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static int __init parse_dt_topology(void)
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{
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struct device_node *cn, *map;
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int ret = 0;
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int cpu;
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cn = of_find_node_by_path("/cpus");
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if (!cn) {
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pr_err("No CPU information found in DT\n");
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return 0;
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}
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/*
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* When topology is provided cpu-map is essentially a root
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* cluster with restricted subnodes.
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*/
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map = of_get_child_by_name(cn, "cpu-map");
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if (!map)
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goto out;
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ret = parse_cluster(map, 0);
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if (ret != 0)
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goto out_map;
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topology_normalize_cpu_scale();
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/*
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* Check that all cores are in the topology; the SMP code will
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* only mark cores described in the DT as possible.
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*/
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for_each_possible_cpu(cpu)
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if (cpu_topology[cpu].package_id == -1)
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ret = -EINVAL;
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out_map:
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of_node_put(map);
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out:
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of_node_put(cn);
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return ret;
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}
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#endif
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/*
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* cpu topology table
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*/
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struct cpu_topology cpu_topology[NR_CPUS];
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EXPORT_SYMBOL_GPL(cpu_topology);
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const struct cpumask *cpu_coregroup_mask(int cpu)
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{
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const cpumask_t *core_mask = cpumask_of_node(cpu_to_node(cpu));
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/* Find the smaller of NUMA, core or LLC siblings */
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if (cpumask_subset(&cpu_topology[cpu].core_sibling, core_mask)) {
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/* not numa in package, lets use the package siblings */
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core_mask = &cpu_topology[cpu].core_sibling;
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}
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if (cpu_topology[cpu].llc_id != -1) {
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if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
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core_mask = &cpu_topology[cpu].llc_sibling;
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}
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return core_mask;
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}
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void update_siblings_masks(unsigned int cpuid)
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{
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struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
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int cpu;
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/* update core and thread sibling masks */
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for_each_online_cpu(cpu) {
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cpu_topo = &cpu_topology[cpu];
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if (cpuid_topo->llc_id == cpu_topo->llc_id) {
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cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
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cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
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}
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if (cpuid_topo->package_id != cpu_topo->package_id)
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continue;
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cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
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cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
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if (cpuid_topo->core_id != cpu_topo->core_id)
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continue;
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cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
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cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
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}
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}
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static void clear_cpu_topology(int cpu)
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{
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struct cpu_topology *cpu_topo = &cpu_topology[cpu];
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cpumask_clear(&cpu_topo->llc_sibling);
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cpumask_set_cpu(cpu, &cpu_topo->llc_sibling);
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cpumask_clear(&cpu_topo->core_sibling);
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cpumask_set_cpu(cpu, &cpu_topo->core_sibling);
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cpumask_clear(&cpu_topo->thread_sibling);
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cpumask_set_cpu(cpu, &cpu_topo->thread_sibling);
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}
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void __init reset_cpu_topology(void)
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{
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unsigned int cpu;
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for_each_possible_cpu(cpu) {
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struct cpu_topology *cpu_topo = &cpu_topology[cpu];
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cpu_topo->thread_id = -1;
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cpu_topo->core_id = -1;
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cpu_topo->package_id = -1;
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cpu_topo->llc_id = -1;
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clear_cpu_topology(cpu);
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}
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}
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void remove_cpu_topology(unsigned int cpu)
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{
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int sibling;
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for_each_cpu(sibling, topology_core_cpumask(cpu))
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cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
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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
|