s390/entry: sort out physical vs virtual pointers usage in sie64a

s390/entry: sort out physical vs virtual pointers usage in sie64a

Fix virtual vs physical address confusion (which currently are the
same).

sie_block is accessed in entry.S and passed it to hardware, which is why
both its physical and virtual address are needed. To avoid every caller
having to do the virtual-physical conversion, add a new function sie64a()
which converts the virtual address to physical.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20221020143159.294605-3-nrb@linux.ibm.com
Message-Id: <20221020143159.294605-3-nrb@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>