[PATCH 09/11] mm/cma: centralize CMA pageblock initialization

[Muchun Song <songmuchun@bytedance.com>]

Early reservations made with cma_reserve_early() currently require callers
to set the pageblock migratetype and update CMA statistics.  These
operations maintain CMA state and should be handled by the CMA core.

Move initialization of early-reserved pageblocks into cma_activate_area(),
alongside the remaining pageblocks.  If activation fails, restore the
managed-page accounting for early-reserved pages because they remain owned
by the caller and are not released by the CMA cleanup path.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/cma.c     | 16 ++++++++++------
 mm/hugetlb.c |  8 +++-----
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/mm/cma.c b/mm/cma.c
index 9ec1d1fd5dff..46e72734ba72 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -163,6 +163,10 @@ static void __init cma_activate_area(struct cma *cma)
 			count = early_pfn[r] - cmr->base_pfn;
 			bitmap_count = cma_bitmap_pages_to_bits(cma, count);
 			bitmap_set(cmr->bitmap, 0, bitmap_count);
+
+			for (pfn = cmr->base_pfn; pfn < early_pfn[r];
+			     pfn += pageblock_nr_pages)
+				init_cma_pageblock(pfn_to_page(pfn));
 		}
 
 		WARN_ON_ONCE(!pfn_valid(cmr->base_pfn));
@@ -191,12 +195,13 @@ static void __init cma_activate_area(struct cma *cma)
 	/* Expose all pages to the buddy, they are useless for CMA. */
 	if (!test_bit(CMA_RESERVE_PAGES_ON_ERROR, &cma->flags)) {
 		for (r = 0; r < cma->nranges; r++) {
-			unsigned long start_pfn;
-
 			cmr = &cma->ranges[r];
-			start_pfn = r <= allocrange ? early_pfn[r] : cmr->early_pfn;
+			end_pfn = r <= allocrange ? early_pfn[r] : cmr->early_pfn;
+			for (pfn = cmr->base_pfn; pfn < end_pfn; pfn++)
+				adjust_managed_page_count(pfn_to_page(pfn), 1);
+
 			end_pfn = cmr->base_pfn + cmr->count;
-			for (pfn = start_pfn; pfn < end_pfn; pfn++)
+			for (; pfn < end_pfn; pfn++)
 				free_reserved_page(pfn_to_page(pfn));
 		}
 	}
@@ -1110,8 +1115,7 @@ bool cma_intersects(struct cma *cma, unsigned long start, unsigned long end)
  *
  * The caller is responsible for initializing the page structures
  * in the area properly, since this just points to memblock-allocated
- * memory. The caller should subsequently use init_cma_pageblock to
- * set the migrate type and CMA stats  the pageblocks that were reserved.
+ * memory.
  *
  * If the CMA area fails to activate later, memory obtained through
  * this interface is not handed to the page allocator, this is
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 290e7859b2d7..ee47a3b09df3 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3240,9 +3240,7 @@ static void __init hugetlb_bootmem_init_migratetype(struct folio *folio,
 	WARN_ON_ONCE(!pageblock_aligned(folio_pfn(folio)));
 
 	for (i = 0; i < nr_pages; i += pageblock_nr_pages) {
-		if (folio_test_hugetlb_cma(folio))
-			init_cma_pageblock(folio_page(folio, i));
-		else
+		if (!folio_test_hugetlb_cma(folio))
 			init_pageblock_migratetype(folio_page(folio, i),
 					  MIGRATE_MOVABLE, false);
 	}
@@ -3305,8 +3303,8 @@ static void __init gather_bootmem_prealloc_node(unsigned long nid)
 		 * in order to fix confusing memory reports from free(1) and
 		 * other side-effects, like CommitLimit going negative.
 		 *
-		 * For CMA pages, this is done in init_cma_pageblock
-		 * (via hugetlb_bootmem_init_migratetype), so skip it here.
+		 * For CMA pages, this is done in cma_activate_area(), so skip
+		 * it here.
 		 */
 		if (hugetlb_early_cma(h))
 			folio_set_hugetlb_cma(folio);
-- 
2.54.0