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 void __init simple_smp_init_cpus(void)
  23 {
  24 }
  25
  26 static int __cpuinit mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
  27 {
  28         unsigned int mpidr, pcpu, pcluster, ret;
  29         extern void secondary_startup(void);
  30
  31         mpidr = cpu_logical_map(cpu);
  32         pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  33         pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
  34         pr_debug("%s: logical CPU %d is physical CPU %d cluster %d\n",
  35                  __func__, cpu, pcpu, pcluster);
  36
  37         mcpm_set_entry_vector(pcpu, pcluster, NULL);
  38         ret = mcpm_cpu_power_up(pcpu, pcluster);
  39         if (ret)
  40                 return ret;
  41         mcpm_set_entry_vector(pcpu, pcluster, secondary_startup);
  42         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
  43         dsb_sev();
  44         return 0;
  45 }
  46
  47 static void __cpuinit mcpm_secondary_init(unsigned int cpu)
  48 {
  49         mcpm_cpu_powered_up();
  50 }
  51
  52 #ifdef CONFIG_HOTPLUG_CPU
  53
  54 static int mcpm_cpu_disable(unsigned int cpu)
  55 {
  56         /*
  57          * We assume all CPUs may be shut down.
  58          * This would be the hook to use for eventual Secure
  59          * OS migration requests as described in the PSCI spec.
  60          */
  61         return 0;
  62 }
  63
  64 static void mcpm_cpu_die(unsigned int cpu)
  65 {
  66         unsigned int mpidr, pcpu, pcluster;
  67         mpidr = read_cpuid_mpidr();
  68         pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  69         pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
  70         mcpm_set_entry_vector(pcpu, pcluster, NULL);
  71         mcpm_cpu_power_down();
  72 }
  73
  74 #endif
  75
  76 static struct smp_operations __initdata mcpm_smp_ops = {
  77         .smp_init_cpus          = simple_smp_init_cpus,
  78         .smp_boot_secondary     = mcpm_boot_secondary,
  79         .smp_secondary_init     = mcpm_secondary_init,
  80 #ifdef CONFIG_HOTPLUG_CPU
  81         .cpu_disable            = mcpm_cpu_disable,
  82         .cpu_die                = mcpm_cpu_die,
  83 #endif
  84 };
  85
  86 void __init mcpm_smp_set_ops(void)
  87 {
  88         smp_set_ops(&mcpm_smp_ops);
  89 }