mm/gup: drop nth_page() usage within folio when recording subpages

nth_page() is no longer required when iterating over pages within a single
folio, so let's just drop it when recording subpages.

Link: https://lkml.kernel.org/r/20250901150359.867252-19-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/gup.c b/mm/gup.c
index ed02d65f9c7254a56b5c025d2716e7493ba64bd1..e1bd2b2e91452e0e465887d05af904966974eba8 100644 (file)
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -488,12 +488,11 @@ static int record_subpages(struct page *page, unsigned long sz,
                           unsigned long addr, unsigned long end,
                           struct page **pages)
 {
-       struct page *start_page;
        int nr;
 
-       start_page = nth_page(page, (addr & (sz - 1)) >> PAGE_SHIFT);
+       page += (addr & (sz - 1)) >> PAGE_SHIFT;
        for (nr = 0; addr != end; nr++, addr += PAGE_SIZE)
-               pages[nr] = nth_page(start_page, nr);
+               pages[nr] = page++;
 
        return nr;
 }
@@ -1512,7 +1511,7 @@ next_page:
                        }
 
                        for (j = 0; j < page_increm; j++) {
-                               subpage = nth_page(page, j);
+                               subpage = page + j;
                                pages[i + j] = subpage;
                                flush_anon_page(vma, subpage, start + j * PAGE_SIZE);
                                flush_dcache_page(subpage);