ARM: 9092/1: xen: Register with kernel restart handler

Register with kernel restart handler instead of setting arm_pm_restart
directly.

Select a high priority of 192 to ensure that default restart handlers
are replaced if Xen is running.
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/xen/enlighten.c

@@ -29,6 +29,7 @@
 #include <linux/cpu.h>
 #include <linux/console.h>
 #include <linux/pvclock_gtod.h>
+#include <linux/reboot.h>
 #include <linux/time64.h>
 #include <linux/timekeeping.h>
 #include <linux/timekeeper_internal.h>
@@ -181,11 +182,18 @@ void xen_reboot(int reason)
 	BUG_ON(rc);
 }
 
-static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
+static int xen_restart(struct notifier_block *nb, unsigned long action,
+		       void *data)
 {
 	xen_reboot(SHUTDOWN_reboot);
+
+	return NOTIFY_DONE;
 }
 
+static struct notifier_block xen_restart_nb = {
+	.notifier_call = xen_restart,
+	.priority = 192,
+};
 
 static void xen_power_off(void)
 {
@@ -404,7 +412,7 @@ static int __init xen_pm_init(void)
 		return -ENODEV;
 
 	pm_power_off = xen_power_off;
-	arm_pm_restart = xen_restart;
+	register_restart_handler(&xen_restart_nb);
 	if (!xen_initial_domain()) {
 		struct timespec64 ts;
 		xen_read_wallclock(&ts);