Add the option to build the code under arch/powerpc with -Werror.

The intention is to make it harder for people to inadvertantly introduce
warnings in the arch/powerpc code. It needs to be configurable so that
if a warning is introduced, people can easily work around it while it's
being fixed.

The option is a negative, ie. don't enable -Werror, so that it will be
turned on for allyes and allmodconfig builds.

The default is n, in the hope that developers will build with -Werror,
that will probably lead to some build breaks, I am prepared to be flamed.

It's not enabled for math-emu, which is a steaming pile of warnings.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Today the arch/powerpc/xmon/setjmp.S file contains only the
xmon_save_regs function.  We want to use it for kdump purposes, so
let's move the file into arch/powerpc/kernel/ and give the function a
more generic name (ppc_save_regs).
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

It may be desireable to build a kernel for cell without
spufs, e.g. as the initial kboot kernel. This requires
that the SPU specific parts of the core dump and the xmon
code depend on CONFIG_SPU_BASE instead of CONFIG_PPC_CELL.
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

While adding spu disassembly support it struck me that we're actually
carrying quite a lot of code around, just to do disassembly in the case
of a crash.

While on large systems it's not an issue, on smaller ones it might be
nice to have xmon - but without the weight of the disassembly support.
For a Cell build this saves ~230KB (!), and for pSeries ~195KB.

We still support the 'di' and 'sdi' commands, however they just dump
the instruction in hex.

Move the definitions into a header to clean xmon.c just a tiny bit.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

This patch adds a "sdi" command to xmon, to disassemble the contents
of an spu's local store.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

This patch unifies udbg for both ppc32 and ppc64 when building the
merged achitecture. xmon now has a single "back end". The powermac udbg
stuff gets enriched with some ADB capabilities and btext output. In
addition, the early_init callback is now called on ppc32 as well,
approx. in the same order as ppc64 regarding device-tree manipulations.
The init sequences of ppc32 and ppc64 are getting closer, I'll unify
them in a later patch.

For now, you can force udbg to the scc using "sccdbg" or to btext using
"btextdbg" on powermacs. I'll implement a cleaner way of forcing udbg
output to something else than the autodetected OF output device in a
later patch.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This factors out the common bits of arch/powerpc/xmon/start_*.c into
a new nonstdio.c, and removes some stuff that was supposed to make
xmon's I/O routines somewhat stdio-like but was never used.

It also makes the parsing of the xmon= command line option common,
so that ppc32 can now use xmon={off,on,early} also.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The merged version follows the ppc64 version pretty closely mostly,
and in fact ARCH=ppc64 now uses the arch/powerpc/xmon version.
The main difference for ppc64 is that the 'p' command to call
show_state (which was always pretty dodgy) has been replaced by
the ppc32 'p' command, which calls a given procedure (so in fact
the old 'p' command behaviour can be achieved with 'p $show_state').
Signed-off-by: NPaul Mackerras <paulus@samba.org>