arch/sh/kernel/idle.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * The idle loop for all SuperH platforms.
   4  *
   5  *  Copyright (C) 2002 - 2009  Paul Mundt
   6  */
   7 #include <linux/cpu.h>
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/mm.h>
  11 #include <linux/pm.h>
  12 #include <linux/tick.h>
  13 #include <linux/preempt.h>
  14 #include <linux/thread_info.h>
  15 #include <linux/irqflags.h>
  16 #include <linux/smp.h>
  17 #include <linux/atomic.h>
  18 #include <asm/processor.h>
  19 #include <asm/smp.h>
  20 #include <asm/bl_bit.h>
  21
  22 static void (*sh_idle)(void);
  23
  24 void default_idle(void)
  25 {
  26         set_bl_bit();
  27         raw_local_irq_enable();
  28         /* Isn't this racy ? */
  29         cpu_sleep();
  30         raw_local_irq_disable();
  31         clear_bl_bit();
  32 }
  33
  34 void __noreturn arch_cpu_idle_dead(void)
  35 {
  36         play_dead();
  37 }
  38
  39 void arch_cpu_idle(void)
  40 {
  41         sh_idle();
  42 }
  43
  44 void __init select_idle_routine(void)
  45 {
  46         /*
  47          * If a platform has set its own idle routine, leave it alone.
  48          */
  49         if (!sh_idle)
  50                 sh_idle = default_idle;
  51 }
  52
  53 void stop_this_cpu(void *unused)
  54 {
  55         local_irq_disable();
  56         set_cpu_online(smp_processor_id(), false);
  57
  58         for (;;)
  59                 cpu_sleep();
  60 }