mm: remove total_mapcount()

All users of total_mapcount() are gone, let's remove it.

Link: https://lkml.kernel.org/r/20240226141324.278526-3-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/mm.h

@@ -1183,7 +1183,7 @@ static inline int is_vmalloc_or_module_addr(const void *x)
  * How many times the entire folio is mapped as a single unit (eg by a
  * PMD or PUD entry).  This is probably not what you want, except for
  * debugging purposes - it does not include PTE-mapped sub-pages; look
- * at folio_mapcount() or page_mapcount() or total_mapcount() instead.
+ * at folio_mapcount() or page_mapcount() instead.
  */
 static inline int folio_entire_mapcount(struct folio *folio)
 {
@@ -1243,13 +1243,6 @@ static inline int folio_mapcount(struct folio *folio)
 	return folio_total_mapcount(folio);
 }
 
-static inline int total_mapcount(struct page *page)
-{
-	if (likely(!PageCompound(page)))
-		return atomic_read(&page->_mapcount) + 1;
-	return folio_total_mapcount(page_folio(page));
-}
-
 static inline bool folio_large_is_mapped(struct folio *folio)
 {
 	/*