This is a significant rework of the XICS driver, too significant to
conveniently break it up into a series of smaller patches to be honest.

The driver is moved to a more generic location to allow new platforms
to use it, and is broken up into separate ICP and ICS "backends". For
now we have the native and "hypervisor" ICP backends and one common
RTAS ICS backend.

The driver supports one ICP backend instanciation, and many ICS ones,
in order to accomodate future platforms with multiple possibly different
interrupt "sources" mechanisms.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There's no need to initialise ppc_md.machine_kexec and
ppc_md.machine_kexec_prepare to the default handlers.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

No one uses ppc_md.machine_crash_shutdown, so remove it.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The pseries_kexec_setup function overwrites some ppc_md
pointers, so make sure it only gets called when running on
the right architecture.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This splits off the kexec path bits of the xics_teardown_cpu() routine
into its own xics_kexec_teardown_cpu() routine.  With the previous
combined routine the CPPR for a cpu that is being removed may have its
CPPR reset in the plpar_eoi() call (which explicitly sets the CPPR to
a non-zero value).  Splitting of the kexec bits of the code prevents
this from happening in the cpu remove path.

Once again, this does not cause the cpu remove from the kernel to
fail, but it does cause cpu dlpar operations to not be able to return
the cpu to the hypervisor.
Signed-off-by: NNathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Commit 2f4dfe20 moved the definition
of hard_smp_processor_id() for the UP case from include/linux/smp.h
to include/asm/smp.h.  However, include/linux/smp.h only includes
include/asm/smp.h in the SMP case, so code that wants to use
hard_smp_processor_id() has to include <asm/smp.h> explicitly to
be sure of getting the definition.
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Move all the pseries kexec code into one file, platforms/pseries/kexec.c
Provide helpers for setting up ppc_md.kexec_cpu_down, so that we don't
have to have #ifdef CONFIG_KEXEC in setup.c

Move the initialisation of the ppc_md kexec callbacks into an init routine.
This is well and truly early enough to cause no change in behaviour, we
can't kexec until userspace has given us a kernel to kexec into.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>