[PATCH v2] mm/hugetlb: mm/memory_hotplug: use a folio in scan_movable_pages()

[Sidhartha Kumar]

By using a folio in scan_movable_pages() we convert the last user of the
page-based hugetlb information macro functions to the folio version.
After this conversion, we can safely remove the page-based definitions
from include/linux/hugetlb.h.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
---

v1 -> v2:
	simplify pfn skipping logic with pfn |= folio_nr_pages(folio) - 1
	per Matthew 

 include/linux/hugetlb.h |  6 +-----
 mm/memory_hotplug.c     | 11 +++++------
 2 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 15a58f69782c..279aca379b95 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -616,9 +616,7 @@ static __always_inline						\
 bool folio_test_hugetlb_##flname(struct folio *folio)		\
 	{	void *private = &folio->private;		\
 		return test_bit(HPG_##flname, private);		\
-	}							\
-static inline int HPage##uname(struct page *page)		\
-	{ return test_bit(HPG_##flname, &(page->private)); }
+	}
 
 #define SETHPAGEFLAG(uname, flname)				\
 static __always_inline						\
@@ -637,8 +635,6 @@ void folio_clear_hugetlb_##flname(struct folio *folio)		\
 #define TESTHPAGEFLAG(uname, flname)				\
 static inline bool						\
 folio_test_hugetlb_##flname(struct folio *folio)		\
-	{ return 0; }						\
-static inline int HPage##uname(struct page *page)		\
 	{ return 0; }
 
 #define SETHPAGEFLAG(uname, flname)				\
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 431b1f6753c0..9c36eb3bbd3b 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1731,8 +1731,8 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
 	unsigned long pfn;
 
 	for (pfn = start; pfn < end; pfn++) {
-		struct page *page, *head;
-		unsigned long skip;
+		struct page *page;
+		struct folio *folio;
 
 		if (!pfn_valid(pfn))
 			continue;
@@ -1753,7 +1753,7 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
 
 		if (!PageHuge(page))
 			continue;
-		head = compound_head(page);
+		folio = page_folio(page);
 		/*
 		 * This test is racy as we hold no reference or lock.  The
 		 * hugetlb page could have been free'ed and head is no longer
@@ -1761,10 +1761,9 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
 		 * cases false positives and negatives are possible.  Calling
 		 * code must deal with these scenarios.
 		 */
-		if (HPageMigratable(head))
+		if (folio_test_hugetlb_migratable(folio))
 			goto found;
-		skip = compound_nr(head) - (pfn - page_to_pfn(head));
-		pfn += skip - 1;
+		pfn |= folio_nr_pages(folio) - 1;
 	}
 	return -ENOENT;
 found:
-- 
2.45.1