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 <linux/irqchip/arm-gic.h>
  19
  20 #include <asm/mcpm.h>
  21 #include <asm/smp.h>
  22 #include <asm/smp_plat.h>
  23
  24 static void __init simple_smp_init_cpus(void)
  25 {
  26 }
  27
  28 static int __cpuinit mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
  29 {
  30         unsigned int mpidr, pcpu, pcluster, ret;
  31         extern void secondary_startup(void);
  32
  33         mpidr = cpu_logical_map(cpu);
  34         pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  35         pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
  36         pr_debug("%s: logical CPU %d is physical CPU %d cluster %d\n",
  37                  __func__, cpu, pcpu, pcluster);
  38
  39         mcpm_set_entry_vector(pcpu, pcluster, NULL);
  40         ret = mcpm_cpu_power_up(pcpu, pcluster);
  41         if (ret)
  42                 return ret;
  43         mcpm_set_entry_vector(pcpu, pcluster, secondary_startup);
  44         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
  45         dsb_sev();
  46         return 0;
  47 }
  48
  49 static void __cpuinit mcpm_secondary_init(unsigned int cpu)
  50 {
  51         mcpm_cpu_powered_up();
  52         gic_secondary_init(0);
  53 }
  54
  55 #ifdef CONFIG_HOTPLUG_CPU
  56
  57 static int mcpm_cpu_disable(unsigned int cpu)
  58 {
  59         /*
  60          * We assume all CPUs may be shut down.
  61          * This would be the hook to use for eventual Secure
  62          * OS migration requests as described in the PSCI spec.
  63          */
  64         return 0;
  65 }
  66
  67 static void mcpm_cpu_die(unsigned int cpu)
  68 {
  69         unsigned int mpidr, pcpu, pcluster;
  70         mpidr = read_cpuid_mpidr();
  71         pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  72         pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
  73         mcpm_set_entry_vector(pcpu, pcluster, NULL);
  74         mcpm_cpu_power_down();
  75 }
  76
  77 #endif
  78
  79 static struct smp_operations __initdata mcpm_smp_ops = {
  80         .smp_init_cpus          = simple_smp_init_cpus,
  81         .smp_boot_secondary     = mcpm_boot_secondary,
  82         .smp_secondary_init     = mcpm_secondary_init,
  83 #ifdef CONFIG_HOTPLUG_CPU
  84         .cpu_disable            = mcpm_cpu_disable,
  85         .cpu_die                = mcpm_cpu_die,
  86 #endif
  87 };
  88
  89 void __init mcpm_smp_set_ops(void)
  90 {
  91         smp_set_ops(&mcpm_smp_ops);
  92 }