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

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