selftests/mm: gup_longterm: add setup of HugeTLB pages

gup_longterm tests skips HugeTLB tests if there are no free huge pages
prepared by a wrapper script.

Add setup of HugeTLB pages to the test and make sure that the original
settings are restored on the test exit.

Link: https://lore.kernel.org/20260511162840.375890-34-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Tested-by: Luiz Capitulino <luizcap@redhat.com>
Tested-by: Sarthak Sharma <sarthak.sharma@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam Howlett <liam@infradead.org>
Cc: Li Wang <li.wang@linux.dev>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/testing/selftests/mm/gup_longterm.c

@@ -510,7 +510,7 @@ int main(int argc, char **argv)
 	int i;
 
 	pagesize = getpagesize();
-	nr_hugetlbsizes = detect_hugetlb_page_sizes(hugetlbsizes,
+	nr_hugetlbsizes = hugetlb_setup(2, hugetlbsizes,
 						    ARRAY_SIZE(hugetlbsizes));
 
 	ksft_print_header();