[PATCH v2] mm/hugetlb: get rid of page_hstate()

[Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>]

Converts the last page_hstate() user to use folio_hstate() so
page_hstate() can be safely removed.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
---
v1->v2:
	-change (page - &folio->page) to folio_page_idx(folio, page)
	 per Matthew Wilcox

 include/linux/hugetlb.h | 10 ----------
 mm/hugetlb.c            |  6 +++---
 mm/page_isolation.c     |  8 ++++----
 3 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 9f4bac3df59e4..0a393bc02f25b 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -841,11 +841,6 @@ static inline struct hstate *folio_hstate(struct folio *folio)
 	return size_to_hstate(folio_size(folio));
 }
 
-static inline struct hstate *page_hstate(struct page *page)
-{
-	return folio_hstate(page_folio(page));
-}
-
 static inline unsigned hstate_index_to_shift(unsigned index)
 {
 	return hstates[index].order + PAGE_SHIFT;
@@ -1062,11 +1057,6 @@ static inline struct hstate *folio_hstate(struct folio *folio)
 	return NULL;
 }
 
-static inline struct hstate *page_hstate(struct page *page)
-{
-	return NULL;
-}
-
 static inline struct hstate *size_to_hstate(unsigned long size)
 {
 	return NULL;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index e0028cbb86c09..154cc5b315727 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1812,10 +1812,10 @@ static void free_hpage_workfn(struct work_struct *work)
 		node = node->next;
 		page->mapping = NULL;
 		/*
-		 * The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate()
-		 * is going to trigger because a previous call to
+		 * The VM_BUG_ON_FOLIO(!folio_test_hugetlb(folio), folio) in
+		 * folio_hstate() is going to trigger because a previous call to
 		 * remove_hugetlb_folio() will call folio_set_compound_dtor
-		 * (folio, NULL_COMPOUND_DTOR), so do not use page_hstate()
+		 * (folio, NULL_COMPOUND_DTOR), so do not use folio_hstate()
 		 * directly.
 		 */
 		h = size_to_hstate(page_size(page));
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 6599cc965e216..bcf99ba747a05 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -79,17 +79,17 @@ static struct page *has_unmovable_pages(unsigned long start_pfn, unsigned long e
 		 * handle each tail page individually in migration.
 		 */
 		if (PageHuge(page) || PageTransCompound(page)) {
-			struct page *head = compound_head(page);
+			struct folio *folio = page_folio(page);
 			unsigned int skip_pages;
 
 			if (PageHuge(page)) {
-				if (!hugepage_migration_supported(page_hstate(head)))
+				if (!hugepage_migration_supported(folio_hstate(folio)))
 					return page;
-			} else if (!PageLRU(head) && !__PageMovable(head)) {
+			} else if (!folio_test_lru(folio) && !__folio_test_movable(folio)) {
 				return page;
 			}
 
-			skip_pages = compound_nr(head) - (page - head);
+			skip_pages = folio_nr_pages(folio) - folio_page_idx(folio, page);
 			pfn += skip_pages - 1;
 			continue;
 		}
-- 
2.41.0