sh: intc: IRQ auto-distribution support.

This implements support for hardware-managed IRQ balancing as implemented
by SH-X3 cores (presently only hooked up for SH7786, but can probably be
carried over to other SH-X3 cores, too).

CPUs need to specify their distribution register along with the mask
definitions, as these follow the same format. Peripheral IRQs that don't
opt out of balancing will be automatically distributed at the whim of the
hardware block, while each CPU needs to verify whether it is handling the
IRQ or not, especially before clearing the mask.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/sh/Kconfig b/drivers/sh/Kconfig
index 22c3cdaf22fe..a54de0b9b3df 100644
--- a/drivers/sh/Kconfig
+++ b/drivers/sh/Kconfig
@@ -11,3 +11,14 @@ config INTC_USERIMASK
           drivers that are using special priority levels.
 
           If in doubt, say N.
+
+config INTC_BALANCING
+        bool "Hardware IRQ balancing support"
+        depends on SMP && SUPERH && CPU_SUBTYPE_SH7786
+        help
+          This enables support for IRQ auto-distribution mode on SH-X3
+          SMP parts. All of the balancing and CPU wakeup decisions are
+          taken care of automatically by hardware for distributed
+          vectors.
+
+          If in doubt, say N.