If system have some mirrored memory and mirrored feature is not specified
in boot parameter, the basic mirrored feature will be enabled and this will
lead to the following situations:

- memblock memory allocation prefers mirrored region. This may have some
  unexpected influence on numa affinity.

- contiguous memory will be split into several parts if parts of them
  is mirrored memory via memblock_mark_mirror().

To fix this, variable mirrored_kernelcore will be checked in
memblock_mark_mirror(). Mark mirrored memory with flag MEMBLOCK_MIRROR iff
kernelcore=mirror is added in the kernel parameters.
Signed-off-by: NMa Wupeng <mawupeng1@huawei.com>
Acked-by: NArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220614092156.1972846-6-mawupeng1@huawei.comAcked-by: NMike Rapoport <rppt@linux.ibm.com>
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>