s390: add support to start the kernel in 64 bit mode.
authorMartin Schwidefsky <[email protected]>
Thu, 23 Aug 2012 14:18:09 +0000 (16:18 +0200)
committerMartin Schwidefsky <[email protected]>
Tue, 9 Oct 2012 12:16:58 +0000 (14:16 +0200)
commit51eee033dca3d6dc81febc5a69f30b964f3bddf3
tree5f5a7b981e2febf38671cb5808e4acddde0005d3
parentcc5b9a45184e90037e6d5353279ec358e57965fd
s390: add support to start the kernel in 64 bit mode.

Do the switch to z/Architecture (alias 64 bit) mode early in head.S.
If the machine is already running in 64 bit mode the sigp turns into
a nop. With this change it doesn't matter in which mode the kernel
is started.

Reviewd-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
arch/s390/kernel/head.S