LXR linux/arch/arm/mach-tango/platsmp.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/delay.h>
   3#include <linux/init.h>
   4#include <linux/smp.h>
   5#include "smc.h"
   6
   7static int tango_boot_secondary(unsigned int cpu, struct task_struct *idle)
   8{
   9        tango_set_aux_boot_addr(__pa_symbol(secondary_startup));
  10        tango_start_aux_core(cpu);
  11        return 0;
  12}
  13
  14#ifdef CONFIG_HOTPLUG_CPU
  15/*
  16 * cpu_kill() and cpu_die() run concurrently on different cores.
  17 * Firmware will only "kill" a core once it has properly "died".
  18 * Try a few times to kill a core before giving up, and sleep
  19 * between tries to give that core enough time to die.
  20 */
  21static int tango_cpu_kill(unsigned int cpu)
  22{
  23        int i, err;
  24
  25        for (i = 0; i < 10; ++i) {
  26                msleep(10);
  27                err = tango_aux_core_kill(cpu);
  28                if (!err)
  29                        return true;
  30        }
  31
  32        return false;
  33}
  34
  35static void tango_cpu_die(unsigned int cpu)
  36{
  37        while (tango_aux_core_die(cpu) < 0)
  38                cpu_relax();
  39
  40        panic("cpu %d failed to die\n", cpu);
  41}
  42#endif
  43
  44static const struct smp_operations tango_smp_ops __initconst = {
  45        .smp_boot_secondary     = tango_boot_secondary,
  46#ifdef CONFIG_HOTPLUG_CPU
  47        .cpu_kill               = tango_cpu_kill,
  48        .cpu_die                = tango_cpu_die,
  49#endif
  50};
  51
  52CPU_METHOD_OF_DECLARE(tango4_smp, "sigma,tango4-smp", &tango_smp_ops);
  53