Subject: [PATCH v2 16/28] s390: introduce arch_zone_limits_init()

From: Mike Rapoport <[email-masked]>
Date: Fri, 2 Jan 2026 08:59:52 +0200

From: "Mike Rapoport (Microsoft)" <[email-masked]>

Move calculations of zone limits to a dedicated arch_zone_limits_init()
function.

Later MM core will use this function as an architecture specific callback
during nodes and zones initialization and thus there won't be a need to
call free_area_init() from every architecture.

Signed-off-by: Mike Rapoport (Microsoft) <[email-masked]>
---
 arch/s390/mm/init.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index e4953453d254..1c11ad84dddb 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -86,6 +86,12 @@ static void __init setup_zero_pages(void)
 	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
 }
 
+void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
+{
+	max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS);
+	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+}
+
 /*
  * paging_init() sets up the page tables
  */
@@ -97,8 +103,7 @@ void __init paging_init(void)
 	sparse_init();
 	zone_dma_limit = DMA_BIT_MASK(31);
 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
-	max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS);
-	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
+	arch_zone_limits_init(max_zone_pfns);
 	free_area_init(max_zone_pfns);
 }
 
-- 
2.51.0