arch/arm/mach-imx/hotplug.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright 2011 Freescale Semiconductor, Inc.
   4  * Copyright 2011 Linaro Ltd.
   5  */
   6
   7 #include <linux/errno.h>
   8 #include <linux/jiffies.h>
   9 #include <asm/cacheflush.h>
  10 #include <asm/cp15.h>
  11 #include <asm/proc-fns.h>
  12
  13 #include "common.h"
  14
  15 /*
  16  * platform-specific code to shutdown a CPU
  17  *
  18  * Called with IRQs disabled
  19  */
  20 void imx_cpu_die(unsigned int cpu)
  21 {
  22         v7_exit_coherency_flush(louis);
  23         /*
  24          * We use the cpu jumping argument register to sync with
  25          * imx_cpu_kill() which is running on cpu0 and waiting for
  26          * the register being cleared to kill the cpu.
  27          */
  28         imx_set_cpu_arg(cpu, ~0);
  29
  30         while (1)
  31                 cpu_do_idle();
  32 }
  33
  34 int imx_cpu_kill(unsigned int cpu)
  35 {
  36         unsigned long timeout = jiffies + msecs_to_jiffies(50);
  37
  38         while (imx_get_cpu_arg(cpu) == 0)
  39                 if (time_after(jiffies, timeout))
  40                         return 0;
  41         imx_enable_cpu(cpu, false);
  42         imx_set_cpu_arg(cpu, 0);
  43         return 1;
  44 }