// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2015 Linus Walleij
 */
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>

#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>

#include "platsmp.h"

#define REALVIEW_SYS_FLAGSSET_OFFSET    0x30

static const struct of_device_id realview_scu_match[] = {
        /*
         * The ARM11MP SCU compatible is only provided as fallback for
         * old RealView EB Cortex-A9 device trees that were using this
         * compatible by mistake.
         */
        { .compatible = "arm,arm11mp-scu", },
        { .compatible = "arm,cortex-a9-scu", },
        { .compatible = "arm,cortex-a5-scu", },
        { }
};

static const struct of_device_id realview_syscon_match[] = {
        { .compatible = "arm,core-module-integrator", },
        { .compatible = "arm,realview-eb-syscon", },
        { .compatible = "arm,realview-pbx-syscon", },
        { },
};

static void __init realview_smp_prepare_cpus(unsigned int max_cpus)
{
        struct device_node *np;
        void __iomem *scu_base;
        struct regmap *map;
        unsigned int ncores;
        int i;

        np = of_find_matching_node(NULL, realview_scu_match);
        if (!np) {
                pr_err("PLATSMP: No SCU base address\n");
                return;
        }
        scu_base = of_iomap(np, 0);
        of_node_put(np);
        if (!scu_base) {
                pr_err("PLATSMP: No SCU remap\n");
                return;
        }

        scu_enable(scu_base);
        ncores = scu_get_core_count(scu_base);
        pr_info("SCU: %d cores detected\n", ncores);
        for (i = 0; i < ncores; i++)
                set_cpu_possible(i, true);
        iounmap(scu_base);

        /* The syscon contains the magic SMP start address registers */
        np = of_find_matching_node(NULL, realview_syscon_match);
        if (!np) {
                pr_err("PLATSMP: No syscon match\n");
                return;
        }
        map = syscon_node_to_regmap(np);
        of_node_put(np);
        if (IS_ERR(map)) {
                pr_err("PLATSMP: No syscon regmap\n");
                return;
        }
        /* Put the boot address in this magic register */
        regmap_write(map, REALVIEW_SYS_FLAGSSET_OFFSET,
                     __pa_symbol(versatile_secondary_startup));
}

#ifdef CONFIG_HOTPLUG_CPU
static void realview_cpu_die(unsigned int cpu)
{
        return versatile_immitation_cpu_die(cpu, 0x20);
}
#endif

static const struct smp_operations realview_dt_smp_ops __initconst = {
        .smp_prepare_cpus       = realview_smp_prepare_cpus,
        .smp_secondary_init     = versatile_secondary_init,
        .smp_boot_secondary     = versatile_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
        .cpu_die                = realview_cpu_die,
#endif
};
CPU_METHOD_OF_DECLARE(realview_smp, "arm,realview-smp", &realview_dt_smp_ops);