My patch to make the early xmon logic work with earlier early param
parsing (480f6f35a149802a94ad5c1a2673ed6ec8d2c158) breaks xmon=off.

No one does this obviously as xmon rocks, but it should really work
as documented.

While fixing that it struck me that we could move the xmon param
handling into xmon.c, and also consolidate the
xmon_init()/do_early_xmon logic into xmon_setup(). This means
xmon=early drops into xmon a little earlier on 32-bit, but it
seems to work just fine.

Tested on PSERIES and CLASSIC32.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

For some reason we have two prototypes for xmon_init(), remove the
one in system.h.

No one calls xmon() anymore, debugger() is preferable, so we don't
need the prototype. And similarly no one calls xmon_printf().

Also update the include guards on xmon.h to match the standard
format, add copyright and license, and add comments to #endifs.

Built for pseries_defconfig and pmac32_defconfig.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul 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: Paul Mackerras <paulus@samba.org>

Building a PowerMac kernel with ARCH=powerpc causes a bunch of warnings,
this fixes some of them

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul 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show_state (which was always pretty dodgy) has been replaced by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: Paul Mackerras <paulus@samba.org>

Xmon itself isn't merged yet, though.

Signed-off-by: Paul Mackerras <paulus@samba.org>