coresight-etm4x: Adding CoreSight ETM4x driver

This driver manages the CoreSight ETMv4 (Embedded Trace Macrocell) IP block
to support HW assisted tracing on ARMv7 and ARMv8 architectures.

Signed-off-by: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index fc1f1ae..8fac01e 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -58,4 +58,15 @@
 	  which allows tracing the instructions that a processor is executing
 	  This is primarily useful for instruction level tracing.  Depending
 	  the ETM version data tracing may also be available.
+
+config CORESIGHT_SOURCE_ETM4X
+	bool "CoreSight Embedded Trace Macrocell 4.x driver"
+	depends on ARM64
+	select CORESIGHT_LINKS_AND_SINKS
+	help
+	  This driver provides support for the ETM4.x tracer module, tracing the
+	  instructions that a processor is executing. This is primarily useful
+	  for instruction level tracing. Depending on the implemented version
+	  data tracing may also be available.
+
 endif