s390/scm_block: allocate aidaw pages only when necessary
authorSebastian Ott <sebott@linux.vnet.ibm.com>
Fri, 5 Dec 2014 15:41:47 +0000 (16:41 +0100)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Mon, 8 Dec 2014 08:42:44 +0000 (09:42 +0100)
commitde88d0d28fe932637eb5b7ebf9e638256cf07979
tree832876b01901d8c29c09ea170bc69f8dacfec25d
parent9d4df77fab7347a74a9938521ffad8d8fab2671d
s390/scm_block: allocate aidaw pages only when necessary

AOBs (the structure describing the HW request) need to be 4K
aligned but very little of that page is actually used. With
this patch we place aidaws at the end of the AOB page and only
allocate a separate page for aidaws when we have to (lists of
aidaws must not cross page boundaries).

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
drivers/s390/block/scm_blk.c
drivers/s390/block/scm_blk.h
drivers/s390/block/scm_blk_cluster.c