s390/vmem: get rid of memory segment list

I can't come up with a satisfying reason why we still need the memory
segment list. We used to represent in the list:
- boot memory
- standby memory added via add_memory()
- loaded dcss segments

When loading/unloading dcss segments, we already track them in a
separate list and check for overlaps
(arch/s390/mm/extmem.c:segment_overlaps_others()) when loading segments.

The overlap check was introduced for some segments in
commit b2300b9efe1b ("[S390] dcssblk: add >2G DCSSs support and stacked
contiguous DCSSs support.")
and was extended to cover all dcss segments in
commit ca57114609d1 ("s390/extmem: remove code for 31 bit addressing
mode").

Although I doubt that overlaps with boot memory and standby memory
are relevant, let's reshuffle the checks in load_segment() to request
the resource first. This will bail out in case we have overlaps with
other resources (esp. boot memory and standby memory). The order
is now different compared to segment_unload() and segment_unload(), but
that should not matter.

This smells like a leftover from ancient times, let's get rid of it. We
can now convert vmem_remove_mapping() into a void function - everybody
ignored the return value already.

Cc: Vasily Gorbik <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Andrew Morton <[email protected]>
Signed-off-by: David Hildenbrand <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Gerald Schaefer <[email protected]>
Tested-by: Gerald Schaefer <[email protected]> [DCSS]
Signed-off-by: Heiko Carstens <[email protected]>

0 files changed, 0 insertions, 0 deletions