// SPDX-License-Identifier: GPL-2.0
/*
 * SMP support for SoCs with SCU covered by mach-shmobile
 *
 * Copyright (C) 2013  Magnus Damm
 */
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include "common.h"


static phys_addr_t shmobile_scu_base_phys;
static void __iomem *shmobile_scu_base;

static int shmobile_scu_cpu_prepare(unsigned int cpu)
{
        /* For this particular CPU register SCU SMP boot vector */
        shmobile_smp_hook(cpu, __pa_symbol(shmobile_boot_scu),
                          shmobile_scu_base_phys);
        return 0;
}

void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys,
                                          unsigned int max_cpus)
{
        /* install boot code shared by all CPUs */
        shmobile_boot_fn = __pa_symbol(shmobile_smp_boot);

        /* enable SCU and cache coherency on booting CPU */
        shmobile_scu_base_phys = scu_base_phys;
        shmobile_scu_base = ioremap(scu_base_phys, PAGE_SIZE);
        scu_enable(shmobile_scu_base);
        scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL);

        /* Use CPU notifier for reset vector control */
        cpuhp_setup_state_nocalls(CPUHP_ARM_SHMOBILE_SCU_PREPARE,
                                  "arm/shmobile-scu:prepare",
                                  shmobile_scu_cpu_prepare, NULL);
}

#ifdef CONFIG_HOTPLUG_CPU
void shmobile_smp_scu_cpu_die(unsigned int cpu)
{
        /* For this particular CPU deregister boot vector */
        shmobile_smp_hook(cpu, 0, 0);

        dsb();
        flush_cache_all();

        /* disable cache coherency */
        scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF);

        /* jump to shared mach-shmobile sleep / reset code */
        shmobile_smp_sleep();
}

static int shmobile_smp_scu_psr_core_disabled(int cpu)
{
        unsigned long mask = SCU_PM_POWEROFF << (cpu * 8);

        if ((readl(shmobile_scu_base + 8) & mask) == mask)
                return 1;

        return 0;
}

int shmobile_smp_scu_cpu_kill(unsigned int cpu)
{
        int k;

        /* this function is running on another CPU than the offline target,
         * here we need wait for shutdown code in platform_cpu_die() to
         * finish before asking SoC-specific code to power off the CPU core.
         */
        for (k = 0; k < 1000; k++) {
                if (shmobile_smp_scu_psr_core_disabled(cpu))
                        return 1;

                mdelay(1);
        }

        return 0;
}
#endif