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
   7 static 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  */
  21 static 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
  35 static 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
  44 static 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
  52 CPU_METHOD_OF_DECLARE(tango4_smp, "sigma,tango4-smp", &tango_smp_ops);