From 343dbdb7cb8997a2cb0fd804d6563b8a6de8d49b Mon Sep 17 00:00:00 2001
From: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Date: Tue, 8 Dec 2020 19:47:15 +0100
Subject: [PATCH] s390/mm: add support to allocate gigantic hugepages using CMA

Commit cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic hugepages
using cma") added support for allocating gigantic hugepages using CMA,
by specifying the hugetlb_cma= kernel parameter, which will disable any
boot-time allocation of gigantic hugepages.

This patch enables that option also for s390.

Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
 arch/s390/kernel/setup.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 756936785598..1f16a03be995 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -49,6 +49,7 @@
 #include <linux/memory.h>
 #include <linux/compat.h>
 #include <linux/start_kernel.h>
+#include <linux/hugetlb.h>
 
 #include <asm/boot_data.h>
 #include <asm/ipl.h>
@@ -1146,6 +1147,8 @@ void __init setup_arch(char **cmdline_p)
 	setup_memory();
 	dma_contiguous_reserve(ident_map_size);
 	vmcp_cma_reserve();
+	if (MACHINE_HAS_EDAT2)
+		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
 
 	check_initrd();
 	reserve_crashkernel();