diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index d96e11ce986c..60aa7e9fe2b9 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -533,6 +533,11 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
  * HPG_freed - Set when page is on the free lists.
  *	Synchronization: hugetlb_lock held for examination and modification.
  * HPG_vmemmap_optimized - Set when the vmemmap pages of the page are freed.
+ * HPG_cma - Set if huge page was directly allocated from CMA area via
+ *	cma_alloc.  Initially set for gigantic page cma allocations, but can
+ *	be set in non-gigantic pages if gigantic pages are demoted.
+ *	Synchronization: Only accessed or modified when there is only one
+ *	reference to the page at allocation, free or demote time.
  */
 enum hugetlb_page_flags {
 	HPG_restore_reserve = 0,
@@ -540,6 +545,7 @@ enum hugetlb_page_flags {
 	HPG_temporary,
 	HPG_freed,
 	HPG_vmemmap_optimized,
+	HPG_cma,
 	__NR_HPAGEFLAGS,
 };
 
@@ -586,6 +592,7 @@ HPAGEFLAG(Migratable, migratable)
 HPAGEFLAG(Temporary, temporary)
 HPAGEFLAG(Freed, freed)
 HPAGEFLAG(VmemmapOptimized, vmemmap_optimized)
+HPAGEFLAG(Cma, cma)
 
 #ifdef CONFIG_HUGETLB_PAGE
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index cebc6dc353f3..d034a223d5d7 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1262,6 +1262,7 @@ static void destroy_compound_gigantic_page(struct page *page,
 	atomic_set(compound_pincount_ptr(page), 0);
 
 	for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
+		p->mapping = NULL;
 		clear_compound_head(p);
 		set_page_refcounted(p);
 	}
@@ -1273,16 +1274,12 @@ static void destroy_compound_gigantic_page(struct page *page,
 
 static void free_gigantic_page(struct page *page, unsigned int order)
 {
-	/*
-	 * If the page isn't allocated using the cma allocator,
-	 * cma_release() returns false.
-	 */
 #ifdef CONFIG_CMA
-	if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order))
-		return;
+	if (HPageCma(page))
+		cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order);
+	else
 #endif
-
-	free_contig_range(page_to_pfn(page), 1 << order);
+		free_contig_range(page_to_pfn(page), 1 << order);
 }
 
 #ifdef CONFIG_CONTIG_ALLOC
@@ -1301,8 +1298,10 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
 		if (hugetlb_cma[nid]) {
 			page = cma_alloc(hugetlb_cma[nid], nr_pages,
 					huge_page_order(h), true);
-			if (page)
+			if (page) {
+				SetHPageCma(page);
 				return page;
+			}
 		}
 
 		if (!(gfp_mask & __GFP_THISNODE)) {
@@ -1312,8 +1311,10 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
 
 				page = cma_alloc(hugetlb_cma[node], nr_pages,
 						huge_page_order(h), true);
-				if (page)
+				if (page) {
+					SetHPageCma(page);
 					return page;
+				}
 			}
 		}
 	}
@@ -1470,6 +1471,20 @@ static void __update_and_free_page(struct hstate *h, struct page *page)
 		destroy_compound_gigantic_page(page, huge_page_order(h));
 		free_gigantic_page(page, huge_page_order(h));
 	} else {
+#ifdef CONFIG_CMA
+		/*
+		 * Could be a page that was demoted from a gigantic page
+		 * which was allocated in a CMA area.
+		 */
+		if (HPageCma(page)) {
+			destroy_compound_gigantic_page(page,
+					huge_page_order(h));
+			if (!cma_release(hugetlb_cma[page_to_nid(page)], page,
+					1 << huge_page_order(h)))
+				VM_BUG_ON_PAGE(1, page);
+			return;
+		}
+#endif
 		__free_pages(page, huge_page_order(h));
 	}
 }
@@ -2981,7 +2996,8 @@ static void __init hugetlb_init_hstates(void)
 		for_each_hstate(h2) {
 			if (h2 == h)
 				continue;
-			if (h2->order < h->order && h2->order > h->demote_order)
+			if (h2->order >= HUGETLB_PAGE_ORDER &&
+			    h2->order < h->order && h2->order > h->demote_order)
 				h->demote_order = h2->order;
 		}
 	}
@@ -6496,7 +6512,13 @@ void __init hugetlb_cma_reserve(int order)
 		size = round_up(size, PAGE_SIZE << order);
 
 		snprintf(name, sizeof(name), "hugetlb%d", nid);
-		res = cma_declare_contiguous_nid(0, size, 0, PAGE_SIZE << order,
+		/*
+		 * Note that 'order per bit' is based on smallest size that
+		 * may be returned to CMA allocator in the case of
+		 * huge page demotion.
+		 */
+		res = cma_declare_contiguous_nid(0, size, 0,
+						PAGE_SIZE << HUGETLB_PAGE_ORDER,
 						 0, false, name,
 						 &hugetlb_cma[nid], nid);
 		if (res) {
