mainline inclusion
from mainline-5.13-rc1
commit b8f871fa
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b8f871fa32ad392759bc70090fa8c60d9f10625c

-------------------------------------------------

Move function is_ldimm64() close to the beginning of libbpf.c,
so it can be reused by later code and the next patch as well.
There is no functionality change.
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204929.3885295-1-yhs@fb.com
(cherry picked from commit b8f871fa)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>