mm: constify page_count and page_ref_count

Now that compound_head() accepts a const struct page pointer, these two
functions can be marked as not modifying the page pointer they are passed.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
Reviewed-by: Anshuman Khandual <[email protected]>
Reviewed-by: William Kucharski <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h
index f3318f34fc54..7ad46f45df39 100644
--- a/include/linux/page_ref.h
+++ b/include/linux/page_ref.h
@@ -62,12 +62,12 @@ static inline void __page_ref_unfreeze(struct page *page, int v)
 
 #endif
 
-static inline int page_ref_count(struct page *page)
+static inline int page_ref_count(const struct page *page)
 {
 	return atomic_read(&page->_refcount);
 }
 
-static inline int page_count(struct page *page)
+static inline int page_count(const struct page *page)
 {
 	return atomic_read(&compound_head(page)->_refcount);
 }