1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * poweroff.c - sysrq handler to gracefully power down machine.
4 */
5
6#include <linux/kernel.h>
7#include <linux/sysrq.h>
8#include <linux/init.h>
9#include <linux/pm.h>
10#include <linux/workqueue.h>
11#include <linux/reboot.h>
12#include <linux/cpumask.h>
13
14/*
15 * When the user hits Sys-Rq o to power down the machine this is the
16 * callback we use.
17 */
18
19static void do_poweroff(struct work_struct *dummy)
20{
21 kernel_power_off();
22}
23
24static DECLARE_WORK(poweroff_work, do_poweroff);
25
26static void handle_poweroff(u8 key)
27{
28 /* run sysrq poweroff on boot cpu */
29 schedule_work_on(cpu: cpumask_first(cpu_online_mask), work: &poweroff_work);
30}
31
32static const struct sysrq_key_op sysrq_poweroff_op = {
33 .handler = handle_poweroff,
34 .help_msg = "poweroff(o)",
35 .action_msg = "Power Off",
36 .enable_mask = SYSRQ_ENABLE_BOOT,
37};
38
39static int __init pm_sysrq_init(void)
40{
41 register_sysrq_key(key: 'o', op: &sysrq_poweroff_op);
42 return 0;
43}
44
45subsys_initcall(pm_sysrq_init);
46