[S390] Add support for memory hot-remove.

This patch enables memory hot-remove on s390.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index 0c2b774..eb5f1b8 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -427,6 +427,8 @@
 			sclp_attach_storage(id);
 	switch (action) {
 	case MEM_ONLINE:
+	case MEM_GOING_OFFLINE:
+	case MEM_CANCEL_OFFLINE:
 		break;
 	case MEM_GOING_ONLINE:
 		rc = sclp_mem_change_state(start, size, 1);
@@ -434,6 +436,9 @@
 	case MEM_CANCEL_ONLINE:
 		sclp_mem_change_state(start, size, 0);
 		break;
+	case MEM_OFFLINE:
+		sclp_mem_change_state(start, size, 0);
+		break;
 	default:
 		rc = -EINVAL;
 		break;