mm: simplify parater of function memmap_init_zone()

As David suggested, simply passing 'struct zone *zone' is enough.  We can
get all needed information from 'struct zone*' easily.

Link: https://lkml.kernel.org/r/20210122135956.5946-4-bhe@redhat.comSigned-off-by: Baoquan He <bhe@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/ia64/mm/init.c

@@ -542,12 +542,14 @@ virtual_memmap_init(u64 start, u64 end, void *arg)
 	return 0;
 }
 
-void __meminit
-memmap_init_zone(unsigned long size, int nid, unsigned long zone,
-	     unsigned long start_pfn)
+void __meminit memmap_init_zone(struct zone *zone)
 {
+	int nid = zone_to_nid(zone), zone_id = zone_idx(zone);
+	unsigned long start_pfn = zone->zone_start_pfn;
+	unsigned long size = zone->spanned_pages;
+
 	if (!vmem_map) {
-		memmap_init_range(size, nid, zone, start_pfn, start_pfn + size,
+		memmap_init_range(size, nid, zone_id, start_pfn, start_pfn + size,
 				 MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
 	} else {
 		struct page *start;
@@ -557,7 +559,7 @@ memmap_init_zone(unsigned long size, int nid, unsigned long zone,
 		args.start = start;
 		args.end = start + size;
 		args.nid = nid;
-		args.zone = zone;
+		args.zone = zone_id;
 
 		efi_memmap_walk(virtual_memmap_init, &args);
 	}

include/linux/mm.h

@@ -2408,8 +2408,7 @@ extern void set_dma_reserve(unsigned long new_dma_reserve);
 extern void memmap_init_range(unsigned long, int, unsigned long,
 		unsigned long, unsigned long, enum meminit_context,
 		struct vmem_altmap *, int migratetype);
-extern void memmap_init_zone(unsigned long size, int nid,
-		unsigned long zone, unsigned long range_start_pfn);
+extern void memmap_init_zone(struct zone *zone);
 extern void setup_per_zone_wmarks(void);
 extern int __meminit init_per_zone_wmark_min(void);
 extern void mem_init(void);

mm/page_alloc.c

@@ -6258,23 +6258,21 @@ static void __meminit zone_init_free_lists(struct zone *zone)
 	}
 }
 
-void __meminit __weak memmap_init_zone(unsigned long size, int nid,
-				  unsigned long zone,
-				  unsigned long range_start_pfn)
+void __meminit __weak memmap_init_zone(struct zone *zone)
 {
+	unsigned long zone_start_pfn = zone->zone_start_pfn;
+	unsigned long zone_end_pfn = zone_start_pfn + zone->spanned_pages;
+	int i, nid = zone_to_nid(zone), zone_id = zone_idx(zone);
 	unsigned long start_pfn, end_pfn;
-	unsigned long range_end_pfn = range_start_pfn + size;
-	int i;
 
 	for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
-		start_pfn = clamp(start_pfn, range_start_pfn, range_end_pfn);
-		end_pfn = clamp(end_pfn, range_start_pfn, range_end_pfn);
+		start_pfn = clamp(start_pfn, zone_start_pfn, zone_end_pfn);
+		end_pfn = clamp(end_pfn, zone_start_pfn, zone_end_pfn);
 
-		if (end_pfn > start_pfn) {
-			size = end_pfn - start_pfn;
-			memmap_init_range(size, nid, zone, start_pfn, range_end_pfn,
-					 MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
-		}
+		if (end_pfn > start_pfn)
+			memmap_init_range(end_pfn - start_pfn, nid,
+					zone_id, start_pfn, zone_end_pfn,
+					MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
 	}
 }
 
@@ -6982,7 +6980,7 @@ static void __init free_area_init_core(struct pglist_data *pgdat)
 		set_pageblock_order();
 		setup_usemap(pgdat, zone, zone_start_pfn, size);
 		init_currently_empty_zone(zone, zone_start_pfn, size);
-		memmap_init_zone(size, nid, j, zone_start_pfn);
+		memmap_init_zone(zone);
 	}
 }