| 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 | |
| 19 | static void do_poweroff(struct work_struct *dummy) |
| 20 | { |
| 21 | kernel_power_off(); |
| 22 | } |
| 23 | |
| 24 | static DECLARE_WORK(poweroff_work, do_poweroff); |
| 25 | |
| 26 | static 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 | |
| 32 | static 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 | |
| 39 | static int __init pm_sysrq_init(void) |
| 40 | { |
| 41 | register_sysrq_key(key: 'o', op: &sysrq_poweroff_op); |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | subsys_initcall(pm_sysrq_init); |
| 46 |