[PATCH 1/3] mm: Constify compound_order() and page_size()

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

These functions do not modify their arguments.  Telling the compiler
this may improve code generation, and allows us to pass const arguments
from other functions.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
---
 include/linux/mm.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 892fe5dbf9de..5ba30a8c6c6d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1036,9 +1036,9 @@ static inline long folio_large_nr_pages(const struct folio *folio)
  * set before the order is initialised, or this may be a tail page.
  * See compaction.c for some good examples.
  */
-static inline unsigned int compound_order(struct page *page)
+static inline unsigned int compound_order(const struct page *page)
 {
-	struct folio *folio = (struct folio *)page;
+	const struct folio *folio = (struct folio *)page;
 
 	if (!test_bit(PG_head, &folio->flags.f))
 		return 0;
@@ -1257,7 +1257,7 @@ int folio_mc_copy(struct folio *dst, struct folio *src);
 unsigned long nr_free_buffer_pages(void);
 
 /* Returns the number of bytes in this potentially compound page. */
-static inline unsigned long page_size(struct page *page)
+static inline unsigned long page_size(const struct page *page)
 {
 	return PAGE_SIZE << compound_order(page);
 }
-- 
2.47.2