FAILED: patch "[PATCH] s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 6b4b54c7ca347bcb4aa7a3cc01aa16e84ac7fbe4 Mon Sep 17 00:00:00 2001
From: Alexander Egorenkov <[email protected]>
Date: Wed, 9 Feb 2022 11:25:09 +0100
Subject: [PATCH] s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE

We need to preserve the values at OLDMEM_BASE and OLDMEM_SIZE which are used by zgetdump in case when kdump crashes. In that case zgetdump will attempt to read OLDMEM_BASE and OLDMEM_SIZE in order to find out where the memory range [0 - OLDMEM_SIZE] belonging to the production kernel is.

index f2c25d113e7b..05327be3a982 100644
@@ -800,6 +800,8 @@ static void __init check_initrd(void)
 static void __init reserve_kernel(void)
 {
 	memblock_reserve(0, STARTUP_NORMAL_OFFSET);
+	memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
+	memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
 	memblock_reserve(__amode31_base, __eamode31 - __samode31);
 	memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
 	memblock_reserve(__pa(_stext), _end - _stext);