v4.19.13 snapshot.
diff --git a/arch/s390/kernel/early_nobss.c b/arch/s390/kernel/early_nobss.c
new file mode 100644
index 0000000..2d84fc4
--- /dev/null
+++ b/arch/s390/kernel/early_nobss.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2007, 2018
+ */
+
+/*
+ * Early setup functions which may not rely on an initialized bss
+ * section. The last thing that is supposed to happen here is
+ * initialization of the bss section.
+ */
+
+#include <linux/processor.h>
+#include <linux/string.h>
+#include <asm/sections.h>
+#include <asm/lowcore.h>
+#include <asm/setup.h>
+#include <asm/timex.h>
+#include "entry.h"
+
+static void __init reset_tod_clock(void)
+{
+ u64 time;
+
+ if (store_tod_clock(&time) == 0)
+ return;
+ /* TOD clock not running. Set the clock to Unix Epoch. */
+ if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
+ disabled_wait(0);
+
+ memset(tod_clock_base, 0, 16);
+ *(__u64 *) &tod_clock_base[1] = TOD_UNIX_EPOCH;
+ S390_lowcore.last_update_clock = TOD_UNIX_EPOCH;
+}
+
+static void __init rescue_initrd(void)
+{
+ unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
+
+ /*
+ * Just like in case of IPL from VM reader we make sure there is a
+ * gap of 4MB between end of kernel and start of initrd.
+ * That way we can also be sure that saving an NSS will succeed,
+ * which however only requires different segments.
+ */
+ if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
+ return;
+ if (!INITRD_START || !INITRD_SIZE)
+ return;
+ if (INITRD_START >= min_initrd_addr)
+ return;
+ memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
+ INITRD_START = min_initrd_addr;
+}
+
+static void __init clear_bss_section(void)
+{
+ memset(__bss_start, 0, __bss_stop - __bss_start);
+}
+
+void __init startup_init_nobss(void)
+{
+ reset_tod_clock();
+ rescue_initrd();
+ clear_bss_section();
+}