MIPS: Octeon: Adding driver to measure interrupt latency on Octeon.

Signed-off-by: Venkat Subbiah <venkat.subbiah@cavium.com>
[Rewrote timeing calculations]
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4660/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index 2f4f6d5..75a6df7 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -94,4 +94,13 @@
 	select NEED_SG_DMA_LENGTH
 
 
+config OCTEON_ILM
+	tristate "Module to measure interrupt latency using Octeon CIU Timer"
+	help
+	  This driver is a module to measure interrupt latency using the
+	  the CIU Timers on Octeon.
+
+	  To compile this driver as a module, choose M here.  The module
+	  will be called octeon-ilm
+
 endif # CPU_CAVIUM_OCTEON