powerpc: Add kconfig for muxed smp ipi support

Compile the new smp ipi mux and demux code only if a platform
will make use of it.  The new config is selected as required.

The new cause_ipi smp op is only available conditionally to point out
configs where the select is required; this makes setting the op an
immediate fail instead of a deferred unresolved symbol at link.

This also creates a new config for power surge powermac upgrade support
that can be disabled in expert mode but is default on.

I also removed the depends / default y on CONFIG_XICS since it is selected
by PSERIES.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 6059053e715..83c704a637b 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -57,6 +57,14 @@ config UDBG_RTAS_CONSOLE
         depends on PPC_RTAS
         default n
 
+config PPC_SMP_MUXED_IPI
+        bool
+        help
+          Select this opton if your platform supports SMP and your
+          interrupt controller provides less than 4 interrupts to each
+          cpu.  This will enable the generic code to multiplex the 4
+          messages on to one ipi.
+
 config PPC_UDBG_BEAT
         bool "BEAT based debug console"
         depends on PPC_CELLEB