[PATCH v4 5/5] mm/hugetlb: add folio_hstate()

[Sidhartha Kumar]

Helper function to retrieve hstate information from a hugetlb folio.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
 include/linux/hugetlb.h | 14 ++++++++++++--
 mm/migrate.c            |  2 +-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index f92b9e6c8f9e..b4473bc43806 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -858,10 +858,15 @@ static inline pte_t arch_make_huge_pte(pte_t entry, unsigned int shift,
 }
 #endif
 
+static inline struct hstate *folio_hstate(struct folio *folio)
+{
+	VM_BUG_ON_FOLIO(!folio_test_hugetlb(folio), folio);
+	return size_to_hstate(folio_size(folio));
+}
+
 static inline struct hstate *page_hstate(struct page *page)
 {
-	VM_BUG_ON_PAGE(!PageHuge(page), page);
-	return size_to_hstate(page_size(page));
+	return folio_hstate(page_folio(page));
 }
 
 static inline unsigned hstate_index_to_shift(unsigned index)
@@ -1070,6 +1075,11 @@ static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
 	return NULL;
 }
 
+static inline struct hstate *folio_hstate(struct folio *folio)
+{
+	return NULL;
+}
+
 static inline struct hstate *page_hstate(struct page *page)
 {
 	return NULL;
diff --git a/mm/migrate.c b/mm/migrate.c
index c228afba0963..17b92af421b9 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1607,7 +1607,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
 		nid = folio_nid(folio);
 
 	if (folio_test_hugetlb(folio)) {
-		struct hstate *h = page_hstate(&folio->page);
+		struct hstate *h = folio_hstate(folio);
 
 		gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
 		return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask);
-- 
2.31.1