LXR linux/arch/arm/common/mcpm

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * linux/arch/arm/mach-vexpress/mcpm_platsmp.c
   4 *
   5 * Created by:  Nicolas Pitre, November 2012
   6 * Copyright:   (C) 2012-2013  Linaro Limited
   7 *
   8 * Code to handle secondary CPU bringup and hotplug for the cluster power API.
   9 */
  10
  11#include <linux/init.h>
  12#include <linux/smp.h>
  13#include <linux/spinlock.h>
  14
  15#include <asm/mcpm.h>
  16#include <asm/smp.h>
  17#include <asm/smp_plat.h>
  18
  19static void cpu_to_pcpu(unsigned int cpu,
  20                        unsigned int *pcpu, unsigned int *pcluster)
  21{
  22        unsigned int mpidr;
  23
  24        mpidr = cpu_logical_map(cpu);
  25        *pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  26        *pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
  27}
  28
  29static int mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
  30{
  31        unsigned int pcpu, pcluster, ret;
  32        extern void secondary_startup(void);
  33
  34        cpu_to_pcpu(cpu, &pcpu, &pcluster);
  35
  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
  49static void mcpm_secondary_init(unsigned int cpu)
  50{
  51        mcpm_cpu_powered_up();
  52}
  53
  54#ifdef CONFIG_HOTPLUG_CPU
  55
  56static int mcpm_cpu_kill(unsigned int cpu)
  57{
  58        unsigned int pcpu, pcluster;
  59
  60        cpu_to_pcpu(cpu, &pcpu, &pcluster);
  61
  62        return !mcpm_wait_for_cpu_powerdown(pcpu, pcluster);
  63}
  64
  65static bool mcpm_cpu_can_disable(unsigned int cpu)
  66{
  67        /* We assume all CPUs may be shut down. */
  68        return true;
  69}
  70
  71static void mcpm_cpu_die(unsigned int cpu)
  72{
  73        unsigned int mpidr, pcpu, pcluster;
  74        mpidr = read_cpuid_mpidr();
  75        pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
  76        pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
  77        mcpm_set_entry_vector(pcpu, pcluster, NULL);
  78        mcpm_cpu_power_down();
  79}
  80
  81#endif
  82
  83static const struct smp_operations mcpm_smp_ops __initconst = {
  84        .smp_boot_secondary     = mcpm_boot_secondary,
  85        .smp_secondary_init     = mcpm_secondary_init,
  86#ifdef CONFIG_HOTPLUG_CPU
  87        .cpu_kill               = mcpm_cpu_kill,
  88        .cpu_can_disable        = mcpm_cpu_can_disable,
  89        .cpu_die                = mcpm_cpu_die,
  90#endif
  91};
  92
  93void __init mcpm_smp_set_ops(void)
  94{
  95        smp_set_ops(&mcpm_smp_ops);
  96}
  97