arch/arm/mach-tango/platsmp.c

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