arch/arm/common/mcpm_platsmp.c

   1 /*
   2  * linux/arch/arm/mach-vexpress/mcpm_platsmp.c
   3  *
   4  * Created by:  Nicolas Pitre, November 2012
   5  * Copyright:   (C) 2012-2013  Linaro Limited
   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  * Code to handle secondary CPU bringup and hotplug for the cluster power API.
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/smp.h>
  16 #include <linux/spinlock.h>
  17
  18 #include <asm/mcpm.h>
  19 #include <asm/smp.h>
  20 #include <asm/smp_plat.h>
  21
  22 static int mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
  23 {
  24         unsigned int mpidr, pcpu, pcluster, ret;
  25         extern void secondary_startup(void);
  26
  27         mpidr = cpu_logical_map(cpu);
  28         pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  29         pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
  30         pr_debug("%s: logical CPU %d is physical CPU %d cluster %d\n",
  31                  __func__, cpu, pcpu, pcluster);
  32
  33         mcpm_set_entry_vector(pcpu, pcluster, NULL);
  34         ret = mcpm_cpu_power_up(pcpu, pcluster);
  35         if (ret)
  36                 return ret;
  37         mcpm_set_entry_vector(pcpu, pcluster, secondary_startup);
  38         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
  39         dsb_sev();
  40         return 0;
  41 }
  42
  43 static void mcpm_secondary_init(unsigned int cpu)
  44 {
  45         mcpm_cpu_powered_up();
  46 }
  47
  48 #ifdef CONFIG_HOTPLUG_CPU
  49
  50 static int mcpm_cpu_disable(unsigned int cpu)
  51 {
  52         /*
  53          * We assume all CPUs may be shut down.
  54          * This would be the hook to use for eventual Secure
  55          * OS migration requests as described in the PSCI spec.
  56          */
  57         return 0;
  58 }
  59
  60 static void mcpm_cpu_die(unsigned int cpu)
  61 {
  62         unsigned int mpidr, pcpu, pcluster;
  63         mpidr = read_cpuid_mpidr();
  64         pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  65         pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
  66         mcpm_set_entry_vector(pcpu, pcluster, NULL);
  67         mcpm_cpu_power_down();
  68 }
  69
  70 #endif
  71
  72 static struct smp_operations __initdata mcpm_smp_ops = {
  73         .smp_boot_secondary     = mcpm_boot_secondary,
  74         .smp_secondary_init     = mcpm_secondary_init,
  75 #ifdef CONFIG_HOTPLUG_CPU
  76         .cpu_disable            = mcpm_cpu_disable,
  77         .cpu_die                = mcpm_cpu_die,
  78 #endif
  79 };
  80
  81 void __init mcpm_smp_set_ops(void)
  82 {
  83         smp_set_ops(&mcpm_smp_ops);
  84 }