[PATCH v2 2/2] mm/mm_init: drop overlap_memmap_init()

[Mike Rapoport]

From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>

When ZONE_NORMAL and ZONE_MOVABLE could overlap because kernelcore=mirror
didn't reduce the span of ZONE_NORMAL, initialization of the memory map had
to skip overlapping pages during initialization of ZONE_MOVABLE to avoid
double initialization of the same struct pages.

Since kernelcore=mirror works now the same way as other variants of
kernelcore=/movablecore=, and adjusts the span of ZONE_NORMAL, there can't
be an overlap between ZONE_NORMAL and ZONE_MOVABLE.

Remove overlap_memmap_init().

Co-developed-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
---
 mm/mm_init.c | 24 ------------------------
 1 file changed, 24 deletions(-)

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 57923dd33d06..838b5a0ad98d 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -799,28 +799,6 @@ void __meminit init_deferred_page(unsigned long pfn, int nid)
 	__init_deferred_page(pfn, nid);
 }
 
-/* If zone is ZONE_MOVABLE but memory is mirrored, it is an overlapped init */
-static bool __meminit
-overlap_memmap_init(unsigned long zone, unsigned long *pfn)
-{
-	static struct memblock_region *r __meminitdata;
-
-	if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
-		if (!r || *pfn >= memblock_region_memory_end_pfn(r)) {
-			for_each_mem_region(r) {
-				if (*pfn < memblock_region_memory_end_pfn(r))
-					break;
-			}
-		}
-		if (*pfn >= memblock_region_memory_base_pfn(r) &&
-		    memblock_is_mirror(r)) {
-			*pfn = memblock_region_memory_end_pfn(r);
-			return true;
-		}
-	}
-	return false;
-}
-
 /*
  * Only struct pages that correspond to ranges defined by memblock.memory
  * are zeroed and initialized by going through __init_single_page() during
@@ -907,8 +885,6 @@ void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone
 		 * function.  They do not exist on hotplugged memory.
 		 */
 		if (context == MEMINIT_EARLY) {
-			if (overlap_memmap_init(zone, &pfn))
-				continue;
 			if (defer_init(nid, pfn, zone_end_pfn)) {
 				deferred_struct_pages = true;
 				break;
-- 
2.53.0