selftests/mm: va_high_addr_switch: add setup of HugeTLB pages

va_high_addr_switch 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/20260511162840.375890-53-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Luiz Capitulino <luizcap@redhat.com>
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/va_high_addr_switch.c

@@ -325,7 +325,7 @@ int main(int argc, char **argv)
 	if (!supported_arch())
 		ksft_exit_skip("Architecture not supported\n");
 
-	if (argc == 2 && !strcmp(argv[1], "--run-hugetlb"))
+	if (hugetlb_setup_default(6))
 		run_hugetlb = true;
 
 	testcases_init();