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, struct tty_struct *tty) 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", 36 .action_msg = "Power Off", 37 .enable_mask = SYSRQ_ENABLE_BOOT, 38 }; 39 40 static int pm_sysrq_init(void) 41 { 42 register_sysrq_key('o', &sysrq_poweroff_op); 43 return 0; 44 } 45 46 subsys_initcall(pm_sysrq_init); 47