/*
 * arch/parisc/kernel/topology.c
 *
 * Copyright (C) 2017 Helge Deller <deller@gmx.de>
 *
 * based on arch/arm/kernel/topology.c
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/sched/topology.h>
#include <linux/cpu.h>

#include <asm/topology.h>
#include <asm/sections.h>

static DEFINE_PER_CPU(struct cpu, cpu_devices);

/*
 * store_cpu_topology is called at boot when only one cpu is running
 * and with the mutex cpu_hotplug.lock locked, when several cpus have booted,
 * which prevents simultaneous write access to cpu_topology array
 */
void store_cpu_topology(unsigned int cpuid)
{
        struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
        struct cpuinfo_parisc *p;
        int max_socket = -1;
        unsigned long cpu;

        /* If the cpu topology has been already set, just return */
        if (cpuid_topo->core_id != -1)
                return;

#ifdef CONFIG_HOTPLUG_CPU
        per_cpu(cpu_devices, cpuid).hotpluggable = 1;
#endif
        if (register_cpu(&per_cpu(cpu_devices, cpuid), cpuid))
                pr_warn("Failed to register CPU%d device", cpuid);

        /* create cpu topology mapping */
        cpuid_topo->thread_id = -1;
        cpuid_topo->core_id = 0;

        p = &per_cpu(cpu_data, cpuid);
        for_each_online_cpu(cpu) {
                const struct cpuinfo_parisc *cpuinfo = &per_cpu(cpu_data, cpu);

                if (cpu == cpuid) /* ignore current cpu */
                        continue;

                if (cpuinfo->cpu_loc == p->cpu_loc) {
                        cpuid_topo->core_id = cpu_topology[cpu].core_id;
                        if (p->cpu_loc) {
                                cpuid_topo->core_id++;
                                cpuid_topo->package_id = cpu_topology[cpu].package_id;
                                continue;
                        }
                }

                if (cpuid_topo->package_id == -1)
                        max_socket = max(max_socket, cpu_topology[cpu].package_id);
        }

        if (cpuid_topo->package_id == -1)
                cpuid_topo->package_id = max_socket + 1;

        update_siblings_masks(cpuid);

        pr_info("CPU%u: cpu core %d of socket %d\n",
                cpuid,
                cpu_topology[cpuid].core_id,
                cpu_topology[cpuid].package_id);
}

/*
 * init_cpu_topology is called at boot when only one cpu is running
 * which prevent simultaneous write access to cpu_topology array
 */
void __init init_cpu_topology(void)
{
        reset_cpu_topology();
}