This patch
- unifies the old sclp early code and the sclp early printk code, so
they can use common functions
- makes sure all sclp early functions and variables have the same
"sclp_early" prefix
- converts the sclp early printk code into readable code by using
existing data structures instead of hard coded magic arrays
- splits the early sclp code into two files: sclp_early.c and
sclp_early_core.c. The core file contains everything that is
required by the kernel decompressor and may not call functions not
contained within the core file. Otherwise the result would be a
link error.
- changes interrupt handling to be completely synchronous. The old
early sclp code had a small window which allowed to receive several
interrupts instead of exactly the single expected interrupt. This
did hide a subtle potential bug, which is fixed with this large
rework.
- contains a couple of small cleanups.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use the early sclp code to provide a boot console. This boot console
is available if the kernel parameter "earlyprintk" has been specified,
just like it works for other architectures that also provide an early
boot console.
This makes debugging of early problems much easier, since now we
finally have working console output even before memory detection is
running.
The boot console will be automatically disabled as soon as another
console will be registered.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
