// 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/cacheinfo.h>
#include <linux/cleanup.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpu_smt.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/sched/topology.h>
#include <linux/cpuset.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/rcupdate.h>
#include <linux/sched.h>
#include <linux/units.h>

#define CREATE_TRACE_POINTS
#include <trace/events/hw_pressure.h>

static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data);
static struct cpumask scale_freq_counters_mask;
static bool scale_freq_invariant;
DEFINE_PER_CPU(unsigned long, capacity_freq_ref) = 0;
EXPORT_PER_CPU_SYMBOL_GPL(capacity_freq_ref);

static bool supports_scale_freq_counters(const struct cpumask *cpus)
{
        int i;

        for_each_cpu(i, cpus) {
                if (cpumask_test_cpu(i, &scale_freq_counters_mask))
                        return true;
        }

        return false;
}

bool topology_scale_freq_invariant(void)
{
        return cpufreq_supports_freq_invariance() ||
               supports_scale_freq_counters(cpu_online_mask);
}

static void update_scale_freq_invariant(bool status)
{
        if (scale_freq_invariant == status)
                return;

        /*
         * Task scheduler behavior depends on frequency invariance support,
         * either cpufreq or counter driven. If the support status changes as
         * a result of counter initialisation and use, retrigger the build of
         * scheduling domains to ensure the information is propagated properly.
         */
        if (topology_scale_freq_invariant() == status) {
                scale_freq_invariant = status;
                rebuild_sched_domains_energy();
        }
}

void topology_set_scale_freq_source(struct scale_freq_data *data,
                                    const struct cpumask *cpus)
{
        struct scale_freq_data *sfd;
        int cpu;

        /*
         * Avoid calling rebuild_sched_domains() unnecessarily if FIE is
         * supported by cpufreq.
         */
        if (cpumask_empty(&scale_freq_counters_mask))
                scale_freq_invariant = topology_scale_freq_invariant();

        rcu_read_lock();

        for_each_cpu(cpu, cpus) {
                sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));

                /* Use ARCH provided counters whenever possible */
                if (!sfd || sfd->source != SCALE_FREQ_SOURCE_ARCH) {
                        rcu_assign_pointer(per_cpu(sft_data, cpu), data);
                        cpumask_set_cpu(cpu, &scale_freq_counters_mask);
                }
        }

        rcu_read_unlock();

        update_scale_freq_invariant(true);
}
EXPORT_SYMBOL_GPL(topology_set_scale_freq_source);

void topology_clear_scale_freq_source(enum scale_freq_source source,
                                      const struct cpumask *cpus)
{
        struct scale_freq_data *sfd;
        int cpu;

        rcu_read_lock();

        for_each_cpu(cpu, cpus) {
                sfd = rcu_dereference(*per_cpu_ptr(&sft_data, cpu));

                if (sfd && sfd->source == source) {
                        rcu_assign_pointer(per_cpu(sft_data, cpu), NULL);
                        cpumask_clear_cpu(cpu, &scale_freq_counters_mask);
                }
        }

        rcu_read_unlock();

        /*
         * Make sure all references to previous sft_data are dropped to avoid
         * use-after-free races.
         */
        synchronize_rcu();

        update_scale_freq_invariant(false);
}
EXPORT_SYMBOL_GPL(topology_clear_scale_freq_source);

void topology_scale_freq_tick(void)
{
        struct scale_freq_data *sfd = rcu_dereference_sched(*this_cpu_ptr(&sft_data));

        if (sfd)
                sfd->set_freq_scale();
}

DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE;
EXPORT_PER_CPU_SYMBOL_GPL(arch_freq_scale);

void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq,
                             unsigned long max_freq)
{
        unsigned long scale;
        int i;

        if (WARN_ON_ONCE(!cur_freq || !max_freq))
                return;

        /*
         * If the use of counters for FIE is enabled, just return as we don't
         * want to update the scale factor with information from CPUFREQ.
         * Instead the scale factor will be updated from arch_scale_freq_tick.
         */
        if (supports_scale_freq_counters(cpus))
                return;

        scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq;

        for_each_cpu(i, cpus)
                per_cpu(arch_freq_scale, i) = scale;
}

DEFINE_PER_CPU(unsigned long, hw_pressure);

/**
 * topology_update_hw_pressure() - Update HW pressure for CPUs
 * @cpus        : The related CPUs for which capacity has been reduced
 * @capped_freq : The maximum allowed frequency that CPUs can run at
 *
 * Update the value of HW pressure for all @cpus in the mask. The
 * cpumask should include all (online+offline) affected CPUs, to avoid
 * operating on stale data when hot-plug is used for some CPUs. The
 * @capped_freq reflects the currently allowed max CPUs frequency due to
 * HW capping. It might be also a boost frequency value, which is bigger
 * than the internal 'capacity_freq_ref' max frequency. In such case the
 * pressure value should simply be removed, since this is an indication that
 * there is no HW throttling. The @capped_freq must be provided in kHz.
 */
void topology_update_hw_pressure(const struct cpumask *cpus,
                                      unsigned long capped_freq)
{
        unsigned long max_capacity, capacity, pressure;
        u32 max_freq;
        int cpu;

        cpu = cpumask_first(cpus);
        max_capacity = arch_scale_cpu_capacity(cpu);
        max_freq = arch_scale_freq_ref(cpu);

        /*
         * Handle properly the boost frequencies, which should simply clean
         * the HW pressure value.
         */
        if (max_freq <= capped_freq)
                capacity = max_capacity;
        else
                capacity = mult_frac(max_capacity, capped_freq, max_freq);

        pressure = max_capacity - capacity;

        trace_hw_pressure_update(cpu, pressure);

        for_each_cpu(cpu, cpus)
                WRITE_ONCE(per_cpu(hw_pressure, cpu), pressure);
}
EXPORT_SYMBOL_GPL(topology_update_hw_pressure);

static void update_topology_flags_workfn(struct work_struct *work);
static DECLARE_WORK(update_topology_flags_work, update_topology_flags_workfn);

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 *raw_capacity;

static int free_raw_capacity(void)
{
        kfree(raw_capacity);
        raw_capacity = NULL;

        return 0;
}

void topology_normalize_cpu_scale(void)
{
        u64 capacity;
        u64 capacity_scale;
        int cpu;

        if (!raw_capacity)
                return;

        capacity_scale = 1;
        for_each_possible_cpu(cpu) {
                capacity = raw_capacity[cpu] *
                           (per_cpu(capacity_freq_ref, cpu) ?: 1);
                capacity_scale = max(capacity, capacity_scale);
        }

        pr_debug("cpu_capacity: capacity_scale=%llu\n", capacity_scale);
        for_each_possible_cpu(cpu) {
                capacity = raw_capacity[cpu] *
                           (per_cpu(capacity_freq_ref, cpu) ?: 1);
                capacity = div64_u64(capacity << 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)
{
        struct clk *cpu_clk;
        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;
                        }
                }
                raw_capacity[cpu] = cpu_capacity;
                pr_debug("cpu_capacity: %pOF cpu_capacity=%u (raw)\n",
                        cpu_node, raw_capacity[cpu]);

                /*
                 * Update capacity_freq_ref for calculating early boot CPU capacities.
                 * For non-clk CPU DVFS mechanism, there's no way to get the
                 * frequency value now, assuming they are running at the same
                 * frequency (by keeping the initial capacity_freq_ref value).
                 */
                cpu_clk = of_clk_get(cpu_node, 0);
                if (!IS_ERR_OR_NULL(cpu_clk)) {
                        per_cpu(capacity_freq_ref, cpu) =
                                clk_get_rate(cpu_clk) / HZ_PER_KHZ;
                        clk_put(cpu_clk);
                }
        } 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;
}

void __weak freq_inv_set_max_ratio(int cpu, u64 max_rate)
{
}

#ifdef CONFIG_ACPI_CPPC_LIB
#include <acpi/cppc_acpi.h>

static inline void topology_init_cpu_capacity_cppc(void)
{
        u64 capacity, capacity_scale = 0;
        struct cppc_perf_caps perf_caps;
        int cpu;

        if (likely(!acpi_cpc_valid()))
                return;

        raw_capacity = kcalloc(num_possible_cpus(), sizeof(*raw_capacity),
                               GFP_KERNEL);
        if (!raw_capacity)
                return;

        for_each_possible_cpu(cpu) {
                if (!cppc_get_perf_caps(cpu, &perf_caps) &&
                    (perf_caps.highest_perf >= perf_caps.nominal_perf) &&
                    (perf_caps.highest_perf >= perf_caps.lowest_perf)) {
                        raw_capacity[cpu] = perf_caps.highest_perf;
                        capacity_scale = max_t(u64, capacity_scale, raw_capacity[cpu]);

                        per_cpu(capacity_freq_ref, cpu) = cppc_perf_to_khz(&perf_caps, raw_capacity[cpu]);

                        pr_debug("cpu_capacity: CPU%d cpu_capacity=%u (raw).\n",
                                 cpu, raw_capacity[cpu]);
                        continue;
                }

                pr_err("cpu_capacity: CPU%d missing/invalid highest performance.\n", cpu);
                pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
                goto exit;
        }

        for_each_possible_cpu(cpu) {
                freq_inv_set_max_ratio(cpu,
                                       per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ);

                capacity = raw_capacity[cpu];
                capacity = div64_u64(capacity << 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));
        }

        schedule_work(&update_topology_flags_work);
        pr_debug("cpu_capacity: cpu_capacity initialization done\n");

exit:
        free_raw_capacity();
}
void acpi_processor_init_invariance_cppc(void)
{
        topology_init_cpu_capacity_cppc();
}
#endif

#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 (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) {
                per_cpu(capacity_freq_ref, cpu) = policy->cpuinfo.max_freq;
                freq_inv_set_max_ratio(cpu,
                                       per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ);
        }

        if (cpumask_empty(cpus_to_visit)) {
                if (raw_capacity) {
                        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 skip registering cpufreq notifier as cpufreq
         * information is not needed for cpu capacity initialization.
         */
        if (!acpi_disabled)
                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)

/* Used to enable the SMT control */
static unsigned int max_smt_thread_num = 1;

/*
 * 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)
{
        int cpu;
        struct device_node *cpu_node __free(device_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));

        return cpu;
}

static int __init parse_core(struct device_node *core, int package_id,
                             int cluster_id, int core_id)
{
        char name[20];
        bool leaf = true;
        int i = 0;
        int cpu;

        do {
                snprintf(name, sizeof(name), "thread%d", i);
                struct device_node *t __free(device_node) =
                        of_get_child_by_name(core, name);

                if (!t)
                        break;

                leaf = false;
                cpu = get_cpu_for_node(t);
                if (cpu >= 0) {
                        cpu_topology[cpu].package_id = package_id;
                        cpu_topology[cpu].cluster_id = cluster_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);
                        return -EINVAL;
                }
                i++;
        } while (1);

        max_smt_thread_num = max_t(unsigned int, max_smt_thread_num, i);

        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].cluster_id = cluster_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 package_id,
                                int cluster_id, int depth)
{
        char name[20];
        bool leaf = true;
        bool has_cores = false;
        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);
                struct device_node *c __free(device_node) =
                        of_get_child_by_name(cluster, name);

                if (!c)
                        break;

                leaf = false;
                ret = parse_cluster(c, package_id, i, depth + 1);
                if (depth > 0)
                        pr_warn("Topology for clusters of clusters not yet supported\n");
                if (ret != 0)
                        return ret;
                i++;
        } while (1);

        /* Now check for cores */
        i = 0;
        do {
                snprintf(name, sizeof(name), "core%d", i);
                struct device_node *c __free(device_node) =
                        of_get_child_by_name(cluster, name);

                if (!c)
                        break;

                has_cores = true;

                if (depth == 0) {
                        pr_err("%pOF: cpu-map children should be clusters\n", c);
                        return -EINVAL;
                }

                if (leaf) {
                        ret = parse_core(c, package_id, cluster_id, core_id++);
                        if (ret != 0)
                                return ret;
                } else {
                        pr_err("%pOF: Non-leaf cluster with core %s\n",
                               cluster, name);
                        return -EINVAL;
                }

                i++;
        } while (1);

        if (leaf && !has_cores)
                pr_warn("%pOF: empty cluster\n", cluster);

        return 0;
}

static int __init parse_socket(struct device_node *socket)
{
        char name[20];
        bool has_socket = false;
        int package_id = 0, ret;

        do {
                snprintf(name, sizeof(name), "socket%d", package_id);
                struct device_node *c __free(device_node) =
                        of_get_child_by_name(socket, name);

                if (!c)
                        break;

                has_socket = true;
                ret = parse_cluster(c, package_id, -1, 0);
                if (ret != 0)
                        return ret;

                package_id++;
        } while (1);

        if (!has_socket)
                ret = parse_cluster(socket, 0, -1, 0);

        /*
         * Reset the max_smt_thread_num to 1 on failure. Since on failure
         * we need to notify the framework the SMT is not supported, but
         * max_smt_thread_num can be initialized to the SMT thread number
         * of the cores which are successfully parsed.
         */
        if (ret)
                max_smt_thread_num = 1;

        cpu_smt_set_num_threads(max_smt_thread_num, max_smt_thread_num);

        return ret;
}

static int __init parse_dt_topology(void)
{
        int ret = 0;
        int cpu;
        struct device_node *cn __free(device_node) =
                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.
         */
        struct device_node *map __free(device_node) =
                of_get_child_by_name(cn, "cpu-map");

        if (!map)
                return ret;

        ret = parse_socket(map);
        if (ret != 0)
                return ret;

        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 < 0) {
                        return -EINVAL;
                }

        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 (last_level_cache_is_valid(cpu)) {
                if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
                        core_mask = &cpu_topology[cpu].llc_sibling;
        }

        /*
         * For systems with no shared cpu-side LLC but with clusters defined,
         * extend core_mask to cluster_siblings. The sched domain builder will
         * then remove MC as redundant with CLS if SCHED_CLUSTER is enabled.
         */
        if (IS_ENABLED(CONFIG_SCHED_CLUSTER) &&
            cpumask_subset(core_mask, &cpu_topology[cpu].cluster_sibling))
                core_mask = &cpu_topology[cpu].cluster_sibling;

        return core_mask;
}

const struct cpumask *cpu_clustergroup_mask(int cpu)
{
        /*
         * Forbid cpu_clustergroup_mask() to span more or the same CPUs as
         * cpu_coregroup_mask().
         */
        if (cpumask_subset(cpu_coregroup_mask(cpu),
                           &cpu_topology[cpu].cluster_sibling))
                return topology_sibling_cpumask(cpu);

        return &cpu_topology[cpu].cluster_sibling;
}

void update_siblings_masks(unsigned int cpuid)
{
        struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
        int cpu, ret;

        ret = detect_cache_attributes(cpuid);
        if (ret && ret != -ENOENT)
                pr_info("Early cacheinfo allocation failed, ret = %d\n", ret);

        /* update core and thread sibling masks */
        for_each_online_cpu(cpu) {
                cpu_topo = &cpu_topology[cpu];

                if (last_level_cache_is_shared(cpu, cpuid)) {
                        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->cluster_id != cpu_topo->cluster_id)
                        continue;

                if (cpuid_topo->cluster_id >= 0) {
                        cpumask_set_cpu(cpu, &cpuid_topo->cluster_sibling);
                        cpumask_set_cpu(cpuid, &cpu_topo->cluster_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->cluster_sibling);
        cpumask_set_cpu(cpu, &cpu_topo->cluster_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->cluster_id = -1;
                cpu_topo->package_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_cluster_cpumask(cpu))
                cpumask_clear_cpu(cpu, topology_cluster_cpumask(sibling));
        for_each_cpu(sibling, topology_llc_cpumask(cpu))
                cpumask_clear_cpu(cpu, topology_llc_cpumask(sibling));

        clear_cpu_topology(cpu);
}

#if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)
struct cpu_smt_info {
        unsigned int thread_num;
        int core_id;
};

static bool __init acpi_cpu_is_threaded(int cpu)
{
        int is_threaded = acpi_pptt_cpu_is_thread(cpu);

        /*
         * if the PPTT doesn't have thread information, check for architecture
         * specific fallback if available
         */
        if (is_threaded < 0)
                is_threaded = arch_cpu_is_threaded();

        return !!is_threaded;
}

/*
 * Propagate the topology information of the processor_topology_node tree to the
 * cpu_topology array.
 */
__weak int __init parse_acpi_topology(void)
{
        unsigned int max_smt_thread_num = 1;
        struct cpu_smt_info *entry;
        struct xarray hetero_cpu;
        unsigned long hetero_id;
        int cpu, topology_id;

        if (acpi_disabled)
                return 0;

        xa_init(&hetero_cpu);

        for_each_possible_cpu(cpu) {
                topology_id = find_acpi_cpu_topology(cpu, 0);
                if (topology_id < 0)
                        return topology_id;

                if (acpi_cpu_is_threaded(cpu)) {
                        cpu_topology[cpu].thread_id = topology_id;
                        topology_id = find_acpi_cpu_topology(cpu, 1);
                        cpu_topology[cpu].core_id   = topology_id;

                        /*
                         * In the PPTT, CPUs below a node with the 'identical
                         * implementation' flag have the same number of threads.
                         * Count the number of threads for only one CPU (i.e.
                         * one core_id) among those with the same hetero_id.
                         * See the comment of find_acpi_cpu_topology_hetero_id()
                         * for more details.
                         *
                         * One entry is created for each node having:
                         * - the 'identical implementation' flag
                         * - its parent not having the flag
                         */
                        hetero_id = find_acpi_cpu_topology_hetero_id(cpu);
                        entry = xa_load(&hetero_cpu, hetero_id);
                        if (!entry) {
                                entry = kzalloc_obj(*entry);
                                WARN_ON_ONCE(!entry);

                                if (entry) {
                                        entry->core_id = topology_id;
                                        entry->thread_num = 1;
                                        xa_store(&hetero_cpu, hetero_id,
                                                 entry, GFP_KERNEL);
                                }
                        } else if (entry->core_id == topology_id) {
                                entry->thread_num++;
                        }
                } else {
                        cpu_topology[cpu].thread_id  = -1;
                        cpu_topology[cpu].core_id    = topology_id;
                }
                topology_id = find_acpi_cpu_topology_cluster(cpu);
                cpu_topology[cpu].cluster_id = topology_id;
                topology_id = find_acpi_cpu_topology_package(cpu);
                cpu_topology[cpu].package_id = topology_id;
        }

        /*
         * This is a short loop since the number of XArray elements is the
         * number of heterogeneous CPU clusters. On a homogeneous system
         * there's only one entry in the XArray.
         */
        xa_for_each(&hetero_cpu, hetero_id, entry) {
                max_smt_thread_num = max(max_smt_thread_num, entry->thread_num);
                xa_erase(&hetero_cpu, hetero_id);
                kfree(entry);
        }

        cpu_smt_set_num_threads(max_smt_thread_num, max_smt_thread_num);
        xa_destroy(&hetero_cpu);
        return 0;
}

void __init init_cpu_topology(void)
{
        int cpu, ret;

        reset_cpu_topology();
        ret = parse_acpi_topology();
        if (!ret)
                ret = of_have_populated_dt() && parse_dt_topology();

        if (ret) {
                /*
                 * Discard anything that was parsed if we hit an error so we
                 * don't use partial information. But do not return yet to give
                 * arch-specific early cache level detection a chance to run.
                 */
                reset_cpu_topology();
        }

        for_each_possible_cpu(cpu) {
                ret = fetch_cache_info(cpu);
                if (!ret)
                        continue;
                else if (ret != -ENOENT)
                        pr_err("Early cacheinfo failed, ret = %d\n", ret);
                return;
        }
}

void store_cpu_topology(unsigned int cpuid)
{
        struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];

        if (cpuid_topo->package_id != -1)
                goto topology_populated;

        cpuid_topo->thread_id = -1;
        cpuid_topo->core_id = cpuid;
        cpuid_topo->package_id = cpu_to_node(cpuid);

        pr_debug("CPU%u: package %d core %d thread %d\n",
                 cpuid, cpuid_topo->package_id, cpuid_topo->core_id,
                 cpuid_topo->thread_id);

topology_populated:
        update_siblings_masks(cpuid);
}
#endif