[PATCH 03/12] mm/sparse: move initialization of section metadata to sparse_metadata_init()

["David Hildenbrand (Arm)" <david@kernel.org>]

Let's move the code responsible for initializing sparse metadata (usemap,
memmap) into a helper. Cleanup the variable while at it (e.g.,
"map_count").

Drop the rather obvious code comments.

No functional change intended.

Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
---
 mm/sparse.c | 43 ++++++++++++++++++++++---------------------
 1 file changed, 22 insertions(+), 21 deletions(-)

diff --git a/mm/sparse.c b/mm/sparse.c
index 36e3d854febc5..a85a9c3840f6c 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -257,38 +257,39 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
 	}
 }
 
+static void __init sparse_metadata_init(void)
+{
+	unsigned long start_section_nr = first_present_section_nr();
+	int nid_begin = sparse_early_nid(__nr_to_section(start_section_nr));
+	unsigned long section_nr, nr_sections = 1;
+
+	for_each_present_section_nr(start_section_nr + 1, section_nr) {
+		const int nid = sparse_early_nid(__nr_to_section(section_nr));
+
+		if (nid == nid_begin) {
+			nr_sections++;
+			continue;
+		}
+		sparse_init_nid(nid_begin, start_section_nr, section_nr, nr_sections);
+		nid_begin = nid;
+		start_section_nr = section_nr;
+		nr_sections = 1;
+	}
+	sparse_init_nid(nid_begin, start_section_nr, section_nr, nr_sections);
+}
+
 /*
  * Allocate the accumulated non-linear sections, allocate a mem_map
  * for each and record the physical to section mapping.
  */
 void __init sparse_init(void)
 {
-	unsigned long pnum_end, pnum_begin, map_count = 1;
-	int nid_begin;
-
 	if (compound_info_has_mask()) {
 		VM_WARN_ON_ONCE(!IS_ALIGNED((unsigned long) pfn_to_page(0),
 				    MAX_FOLIO_VMEMMAP_ALIGN));
 	}
 
-	pnum_begin = first_present_section_nr();
-	nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
-
-	for_each_present_section_nr(pnum_begin + 1, pnum_end) {
-		int nid = sparse_early_nid(__nr_to_section(pnum_end));
-
-		if (nid == nid_begin) {
-			map_count++;
-			continue;
-		}
-		/* Init node with sections in range [pnum_begin, pnum_end) */
-		sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
-		nid_begin = nid;
-		pnum_begin = pnum_end;
-		map_count = 1;
-	}
-	/* cover the last node */
-	sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
+	sparse_metadata_init();
 	sparse_init_subsection_map();
 	vmemmap_populate_print_last();
 }

-- 
2.43.0