LXR linux/arch/arm/mach-vexpress/platsmp.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  linux/arch/arm/mach-vexpress/platsmp.c
   4 *
   5 *  Copyright (C) 2002 ARM Ltd.
   6 *  All Rights Reserved
   7 */
   8#include <linux/init.h>
   9#include <linux/errno.h>
  10#include <linux/smp.h>
  11#include <linux/io.h>
  12#include <linux/of_address.h>
  13#include <linux/vexpress.h>
  14
  15#include <asm/mcpm.h>
  16#include <asm/smp_scu.h>
  17#include <asm/mach/map.h>
  18
  19#include <plat/platsmp.h>
  20
  21#include "core.h"
  22
  23bool __init vexpress_smp_init_ops(void)
  24{
  25#ifdef CONFIG_MCPM
  26        int cpu;
  27        struct device_node *cpu_node, *cci_node;
  28
  29        /*
  30         * The best way to detect a multi-cluster configuration
  31         * is to detect if the kernel can take over CCI ports
  32         * control. Loop over possible CPUs and check if CCI
  33         * port control is available.
  34         * Override the default vexpress_smp_ops if so.
  35         */
  36        for_each_possible_cpu(cpu) {
  37                bool available;
  38
  39                cpu_node = of_get_cpu_node(cpu, NULL);
  40                if (WARN(!cpu_node, "Missing cpu device node!"))
  41                        return false;
  42
  43                cci_node = of_parse_phandle(cpu_node, "cci-control-port", 0);
  44                available = cci_node && of_device_is_available(cci_node);
  45                of_node_put(cci_node);
  46                of_node_put(cpu_node);
  47
  48                if (!available)
  49                        return false;
  50        }
  51
  52        mcpm_smp_set_ops();
  53        return true;
  54#else
  55        return false;
  56#endif
  57}
  58
  59static const struct of_device_id vexpress_smp_dt_scu_match[] __initconst = {
  60        { .compatible = "arm,cortex-a5-scu", },
  61        { .compatible = "arm,cortex-a9-scu", },
  62        {}
  63};
  64
  65static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)
  66{
  67        struct device_node *scu = of_find_matching_node(NULL,
  68                        vexpress_smp_dt_scu_match);
  69
  70        if (scu)
  71                scu_enable(of_iomap(scu, 0));
  72
  73        /*
  74         * Write the address of secondary startup into the
  75         * system-wide flags register. The boot monitor waits
  76         * until it receives a soft interrupt, and then the
  77         * secondary CPU branches to this address.
  78         */
  79        vexpress_flags_set(__pa_symbol(versatile_secondary_startup));
  80}
  81
  82#ifdef CONFIG_HOTPLUG_CPU
  83static void vexpress_cpu_die(unsigned int cpu)
  84{
  85        versatile_immitation_cpu_die(cpu, 0x40);
  86}
  87#endif
  88
  89const struct smp_operations vexpress_smp_dt_ops __initconst = {
  90        .smp_prepare_cpus       = vexpress_smp_dt_prepare_cpus,
  91        .smp_secondary_init     = versatile_secondary_init,
  92        .smp_boot_secondary     = versatile_boot_secondary,
  93#ifdef CONFIG_HOTPLUG_CPU
  94        .cpu_die                = vexpress_cpu_die,
  95#endif
  96};
  97