[PATCH v5 2/5] mm: skip non-mirrored ZONE_NORMAL memory map init when kernelcore=mirror

[Yuan Liu]

Mirrored regions are already skipped when initializing ZONE_MOVABLE, but
overlapping PFNs can still be initialized from the ZONE_NORMAL path when
ZONE_MOVABLE is present on the node.

When zone_movable_pfn[nid] is set, skip ZONE_NORMAL initialization for
non-mirrored regions, keep skipping mirrored regions for ZONE_MOVABLE.

Reviewed-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Reviewed-by: Jason Zeng <jason.zeng@xxxxxxxxx>
Co-developed-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Signed-off-by: Yuan Liu <yuan1.liu@xxxxxxxxx>
---
 mm/mm_init.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 24e103a402b0..2a5ac175d5dd 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -941,9 +941,18 @@ static void __init memmap_init(void)
 			if (!populated_zone(zone))
 				continue;
 
-			if (mirrored_kernelcore && j == ZONE_MOVABLE &&
-			    memblock_is_mirror(r))
-				continue;
+			if (mirrored_kernelcore) {
+				/*
+				 * Avoid double initialization of PFNs that overlap
+				 * between Normal and Movable zones.
+				 */
+				if (j == ZONE_NORMAL && !memblock_is_mirror(r) &&
+				    zone_movable_pfn[nid])
+					continue;
+
+				if (j == ZONE_MOVABLE && memblock_is_mirror(r))
+					continue;
+			}
 
 			memmap_init_zone_range(zone, start_pfn, end_pfn,
 					       &hole_pfn);
-- 
2.47.3