[S390] Add PSW restart shutdown trigger

With this patch a new S390 shutdown trigger "restart" is added. If under
z/VM "systerm restart" is entered or under the HMC the "PSW restart" button
is pressed, the PSW located at 0 (31 bit) or 0x1a0 (64 bit) bit is loaded.
Now we execute do_restart() that processes the restart action that is
defined under /sys/firmware/shutdown_actions/on_restart. Currently the
following actions are possible: reipl (default), stop, vmcmd, dump, and
dump_reipl.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 38 insertions, 1 deletions

diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index a689070be287..059c59027ac0 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -45,11 +45,13 @@
  * - halt
  * - power off
  * - reipl
+ * - restart
  */
 #define ON_PANIC_STR		"on_panic"
 #define ON_HALT_STR		"on_halt"
 #define ON_POFF_STR		"on_poff"
 #define ON_REIPL_STR		"on_reboot"
+#define ON_RESTART_STR		"on_restart"
 
 struct shutdown_action;
 struct shutdown_trigger {
@@ -1544,17 +1546,20 @@ static char vmcmd_on_reboot[128];
 static char vmcmd_on_panic[128];
 static char vmcmd_on_halt[128];
 static char vmcmd_on_poff[128];
+static char vmcmd_on_restart[128];
 
 DEFINE_IPL_ATTR_STR_RW(vmcmd, on_reboot, "%s\n", "%s\n", vmcmd_on_reboot);
 DEFINE_IPL_ATTR_STR_RW(vmcmd, on_panic, "%s\n", "%s\n", vmcmd_on_panic);
 DEFINE_IPL_ATTR_STR_RW(vmcmd, on_halt, "%s\n", "%s\n", vmcmd_on_halt);
 DEFINE_IPL_ATTR_STR_RW(vmcmd, on_poff, "%s\n", "%s\n", vmcmd_on_poff);
+DEFINE_IPL_ATTR_STR_RW(vmcmd, on_restart, "%s\n", "%s\n", vmcmd_on_restart);
 
 static struct attribute *vmcmd_attrs[] = {
 	&sys_vmcmd_on_reboot_attr.attr,
 	&sys_vmcmd_on_panic_attr.attr,
 	&sys_vmcmd_on_halt_attr.attr,
 	&sys_vmcmd_on_poff_attr.attr,
+	&sys_vmcmd_on_restart_attr.attr,
 	NULL,
 };
 
@@ -1576,6 +1581,8 @@ static void vmcmd_run(struct shutdown_trigger *trigger)
 		cmd = vmcmd_on_halt;
 	else if (strcmp(trigger->name, ON_POFF_STR) == 0)
 		cmd = vmcmd_on_poff;
+	else if (strcmp(trigger->name, ON_RESTART_STR) == 0)
+		cmd = vmcmd_on_restart;
 	else
 		return;
 
@@ -1707,6 +1714,34 @@ static void do_panic(void)
 	stop_run(&on_panic_trigger);
 }
 
+/* on restart */
+
+static struct shutdown_trigger on_restart_trigger = {ON_RESTART_STR,
+	&reipl_action};
+
+static ssize_t on_restart_show(struct kobject *kobj,
+			       struct kobj_attribute *attr, char *page)
+{
+	return sprintf(page, "%s\n", on_restart_trigger.action->name);
+}
+
+static ssize_t on_restart_store(struct kobject *kobj,
+				struct kobj_attribute *attr,
+				const char *buf, size_t len)
+{
+	return set_trigger(buf, &on_restart_trigger, len);
+}
+
+static struct kobj_attribute on_restart_attr =
+	__ATTR(on_restart, 0644, on_restart_show, on_restart_store);
+
+void do_restart(void)
+{
+	smp_send_stop();
+	on_restart_trigger.action->fn(&on_restart_trigger);
+	stop_run(&on_restart_trigger);
+}
+
 /* on halt */
 
 static struct shutdown_trigger on_halt_trigger = {ON_HALT_STR, &stop_action};
@@ -1783,7 +1818,9 @@ static void __init shutdown_triggers_init(void)
 	if (sysfs_create_file(&shutdown_actions_kset->kobj,
 			      &on_poff_attr.attr))
 		goto fail;
-
+	if (sysfs_create_file(&shutdown_actions_kset->kobj,
+			      &on_restart_attr.attr))
+		goto fail;
 	return;
 fail:
 	panic("shutdown_triggers_init failed\n");