kernel/power/poweroff.c

   1 /*
   2  * poweroff.c - sysrq handler to gracefully power down machine.
   3  *
   4  * This file is released under the GPL v2
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/sysrq.h>
   9 #include <linux/init.h>
  10 #include <linux/pm.h>
  11 #include <linux/workqueue.h>
  12 #include <linux/reboot.h>
  13 #include <linux/cpumask.h>
  14
  15 /*
  16  * When the user hits Sys-Rq o to power down the machine this is the
  17  * callback we use.
  18  */
  19
  20 static void do_poweroff(struct work_struct *dummy)
  21 {
  22         kernel_power_off();
  23 }
  24
  25 static DECLARE_WORK(poweroff_work, do_poweroff);
  26
  27 static void handle_poweroff(int key)
  28 {
  29         /* run sysrq poweroff on boot cpu */
  30         schedule_work_on(cpumask_first(cpu_online_mask), &poweroff_work);
  31 }
  32
  33 static struct sysrq_key_op      sysrq_poweroff_op = {
  34         .handler        = handle_poweroff,
  35         .help_msg       = "poweroff(o)",
  36         .action_msg     = "Power Off",
  37         .enable_mask    = SYSRQ_ENABLE_BOOT,
  38 };
  39
  40 static int __init pm_sysrq_init(void)
  41 {
  42         register_sysrq_key('o', &sysrq_poweroff_op);
  43         return 0;
  44 }
  45
  46 subsys_initcall(pm_sysrq_init);