[PATCH v4 1/2] mm: move overlap memory map init check to memmap_init()

[Yuan Liu]

Move the overlap memmap init check from memmap_init_range() into
memmap_init().

When mirrored kernelcore is enabled, avoid memory map initialization
for overlap regions. There are two cases that may overlap: a mirror
memory region assigned to movable zone, or a non-mirror memory region
assigned to a non-movable zone but falling within the movable zone
range.

Signed-off-by: Yuan Liu <yuan1.liu@xxxxxxxxx>
---
 mm/mm_init.c | 37 +++++++++++++------------------------
 1 file changed, 13 insertions(+), 24 deletions(-)

diff --git a/mm/mm_init.c b/mm/mm_init.c
index df34797691bd..2b5233060504 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -797,28 +797,6 @@ void __meminit reserve_bootmem_region(phys_addr_t start,
 	}
 }
 
-/* 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;
-
-	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
@@ -905,8 +883,6 @@ 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;
@@ -971,6 +947,7 @@ static void __init memmap_init(void)
 
 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
 		struct pglist_data *node = NODE_DATA(nid);
+		struct memblock_region *r = &memblock.memory.regions[i];
 
 		for (j = 0; j < MAX_NR_ZONES; j++) {
 			struct zone *zone = node->node_zones + j;
@@ -978,6 +955,18 @@ static void __init memmap_init(void)
 			if (!populated_zone(zone))
 				continue;
 
+			if (mirrored_kernelcore) {
+				const bool is_mirror = memblock_is_mirror(r);
+				const bool is_movable_zone = (j == ZONE_MOVABLE);
+
+				if (is_mirror && is_movable_zone)
+					continue;
+
+				if (!is_mirror && !is_movable_zone &&
+				    start_pfn >= zone_movable_pfn[nid])
+					continue;
+			}
+
 			memmap_init_zone_range(zone, start_pfn, end_pfn,
 					       &hole_pfn);
 			zone_id = j;
-- 
2.47.3