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
  26 bool __init vexpress_smp_init_ops(void)
  27 {
  28 #ifdef CONFIG_MCPM
  29         /*
  30          * The best way to detect a multi-cluster configuration at the moment
  31          * is to look for the presence of a CCI in the system.
  32          * Override the default vexpress_smp_ops if so.
  33          */
  34         struct device_node *node;
  35         node = of_find_compatible_node(NULL, NULL, "arm,cci-400");
  36         if (node && of_device_is_available(node)) {
  37                 mcpm_smp_set_ops();
  38                 return true;
  39         }
  40 #endif
  41         return false;
  42 }
  43
  44 static const struct of_device_id vexpress_smp_dt_scu_match[] __initconst = {
  45         { .compatible = "arm,cortex-a5-scu", },
  46         { .compatible = "arm,cortex-a9-scu", },
  47         {}
  48 };
  49
  50 static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)
  51 {
  52         struct device_node *scu = of_find_matching_node(NULL,
  53                         vexpress_smp_dt_scu_match);
  54
  55         if (scu)
  56                 scu_enable(of_iomap(scu, 0));
  57
  58         /*
  59          * Write the address of secondary startup into the
  60          * system-wide flags register. The boot monitor waits
  61          * until it receives a soft interrupt, and then the
  62          * secondary CPU branches to this address.
  63          */
  64         vexpress_flags_set(virt_to_phys(versatile_secondary_startup));
  65 }
  66
  67 const struct smp_operations vexpress_smp_dt_ops __initconst = {
  68         .smp_prepare_cpus       = vexpress_smp_dt_prepare_cpus,
  69         .smp_secondary_init     = versatile_secondary_init,
  70         .smp_boot_secondary     = versatile_boot_secondary,
  71 #ifdef CONFIG_HOTPLUG_CPU
  72         .cpu_die                = vexpress_cpu_die,
  73 #endif
  74 };