[PATCH 3/3] mm/hugetlb: Refactor __unmap_hugepage_range() to take folio instead of page

[nifan.cxl@gmail.com]

From: Fan Ni <fan.ni@samsung.com>

The function __unmap_hugepage_range() has two kinds of users:
1) unmap_hugepage_range(), which passes in the head page of a folio.
   Since unmap_hugepage_range() already takes folio and there are no other
   uses of the folio struct in the function, it is natural for
   __unmap_hugepage_range() to take folio also.
2) All other uses, which pass in NULL pointer.

In both cases, we can pass in folio. Refactor __unmap_hugepage_range() to
take folio.

Signed-off-by: Fan Ni <fan.ni@samsung.com>
---

Question: If the change in the patch makes sense, should we try to convert all
"page" uses in __unmap_hugepage_range() to folio?

---
 include/linux/hugetlb.h |  2 +-
 mm/hugetlb.c            | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index b7699f35c87f..d6c503dd2f7d 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -133,7 +133,7 @@ void unmap_hugepage_range(struct vm_area_struct *,
 void __unmap_hugepage_range(struct mmu_gather *tlb,
 			  struct vm_area_struct *vma,
 			  unsigned long start, unsigned long end,
-			  struct page *ref_page, zap_flags_t zap_flags);
+			  struct folio *ref_folio, zap_flags_t zap_flags);
 void hugetlb_report_meminfo(struct seq_file *);
 int hugetlb_report_node_meminfo(char *buf, int len, int nid);
 void hugetlb_show_meminfo_node(int nid);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3181dbe0c4bb..7d280ab23784 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5833,7 +5833,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
 
 void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 			    unsigned long start, unsigned long end,
-			    struct page *ref_page, zap_flags_t zap_flags)
+			    struct folio *ref_folio, zap_flags_t zap_flags)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	unsigned long address;
@@ -5910,8 +5910,8 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		 * page is being unmapped, not a range. Ensure the page we
 		 * are about to unmap is the actual page of interest.
 		 */
-		if (ref_page) {
-			if (page != ref_page) {
+		if (ref_folio) {
+			if (page != folio_page(ref_folio, 0)) {
 				spin_unlock(ptl);
 				continue;
 			}
@@ -5977,7 +5977,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		/*
 		 * Bail out after unmapping reference page if supplied
 		 */
-		if (ref_page)
+		if (ref_folio)
 			break;
 	}
 	tlb_end_vma(tlb, vma);
@@ -6052,7 +6052,7 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
 	tlb_gather_mmu(&tlb, vma->vm_mm);
 
 	__unmap_hugepage_range(&tlb, vma, start, end,
-			       folio_page(ref_folio, 0), zap_flags);
+			       ref_folio, zap_flags);
 
 	mmu_notifier_invalidate_range_end(&range);
 	tlb_finish_mmu(&tlb);
-- 
2.47.2