fixup: selftests/mm: use nr_pages instead of 1UL << order

reduce code duplication, per David

Link: https://lkml.kernel.org/r/F54782D6-65A3-4D35-AE03-8ADE636EE258@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c
index 432cf434ca961c085adb60ee2d3bd24cdcb3df8f..7be06dae663ed6ebe593dd2d3c04041b7d0deb04 100644 (file)
--- a/tools/testing/selftests/mm/split_huge_page_test.c
+++ b/tools/testing/selftests/mm/split_huge_page_test.c
@@ -38,6 +38,7 @@ unsigned int pmd_order;
 static bool is_backed_by_folio(char *vaddr, int order, int pagemap_fd,
                int kpageflags_fd)
 {
+       const unsigned long nr_pages = 1UL << order;
        unsigned long pfn_head;
        uint64_t pfn_flags;
        unsigned long pfn;
@@ -63,7 +64,7 @@ static bool is_backed_by_folio(char *vaddr, int order, int pagemap_fd,
        if (!(pfn_flags & KPF_THP))
                return false;
 
-       pfn_head = pfn & ~((1 << order) - 1);
+       pfn_head = pfn & ~(nr_pages - 1);
 
        if (pageflags_get(pfn_head, kpageflags_fd, &pfn_flags))
                goto fail;
@@ -73,7 +74,7 @@ static bool is_backed_by_folio(char *vaddr, int order, int pagemap_fd,
                return false;
 
        /* check all tail PFN flags */
-       for (i = 1; i < 1UL << order; i++) {
+       for (i = 1; i < nr_pages; i++) {
                if (pageflags_get(pfn_head + i, kpageflags_fd, &pfn_flags))
                        goto fail;
                if (!(pfn_flags & (KPF_THP | KPF_COMPOUND_TAIL)))
@@ -84,7 +85,7 @@ static bool is_backed_by_folio(char *vaddr, int order, int pagemap_fd,
         * check the PFN after this folio, but if its flags cannot be obtained,
         * assume this folio has the expected order
         */
-       if (pageflags_get(pfn_head + (1UL << order), kpageflags_fd, &pfn_flags))
+       if (pageflags_get(pfn_head + nr_pages, kpageflags_fd, &pfn_flags))
                return true;
 
        /* this folio is bigger than the given order */