1 files changed, 45 insertions, 0 deletions
diff --git a/kernel/power/poweroff.c b/kernel/power/poweroff.c
new file mode 100644
index 0000000000..1f306f1586
--- /dev/null
+++ b/kernel/power/poweroff.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * poweroff.c - sysrq handler to gracefully power down machine.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sysrq.h>
+#include <linux/init.h>
+#include <linux/pm.h>
+#include <linux/workqueue.h>
+#include <linux/reboot.h>
+#include <linux/cpumask.h>
+
+/*
+ * When the user hits Sys-Rq o to power down the machine this is the
+ * callback we use.
+ */
+
+static void do_poweroff(struct work_struct *dummy)
+{
+	kernel_power_off();
+}
+
+static DECLARE_WORK(poweroff_work, do_poweroff);
+
+static void handle_poweroff(u8 key)
+{
+	/* run sysrq poweroff on boot cpu */
+	schedule_work_on(cpumask_first(cpu_online_mask), &poweroff_work);
+}
+
+static const struct sysrq_key_op	sysrq_poweroff_op = {
+	.handler        = handle_poweroff,
+	.help_msg       = "poweroff(o)",
+	.action_msg     = "Power Off",
+	.enable_mask	= SYSRQ_ENABLE_BOOT,
+};
+
+static int __init pm_sysrq_init(void)
+{
+	register_sysrq_key('o', &sysrq_poweroff_op);
+	return 0;
+}
+
+subsys_initcall(pm_sysrq_init);