coresight: Grouping all perf tools oriented section together

This patch groups together section pertaining to the perf tools.  That way
everything is at the same place rather than spread out.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/trace/coresight.txt

@@ -345,42 +345,7 @@ More information on the above and other example on how to use Coresight with
 the perf tools can be found in the "HOWTO.md" file of the openCSD gitHub
 repository [3].
 
-How to use the STM module
--------------------------
-
-Using the System Trace Macrocell module is the same as the tracers - the only
-difference is that clients are driving the trace capture rather
-than the program flow through the code.
-
-As with any other CoreSight component, specifics about the STM tracer can be
-found in sysfs with more information on each entry being found in [1]:
-
-root@genericarmv8:~# ls /sys/bus/coresight/devices/20100000.stm
-enable_source   hwevent_select  port_enable     subsystem       uevent
-hwevent_enable  mgmt            port_select     traceid
-root@genericarmv8:~#
-
-Like any other source a sink needs to be identified and the STM enabled before
-being used:
-
-root@genericarmv8:~# echo 1 > /sys/bus/coresight/devices/20010000.etf/enable_sink
-root@genericarmv8:~# echo 1 > /sys/bus/coresight/devices/20100000.stm/enable_source
-
-From there user space applications can request and use channels using the devfs
-interface provided for that purpose by the generic STM API:
-
-root@genericarmv8:~# ls -l /dev/20100000.stm
-crw-------    1 root     root       10,  61 Jan  3 18:11 /dev/20100000.stm
-root@genericarmv8:~#
-
-Details on how to use the generic STM API can be found here [2].
-
-[1]. Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
-[2]. Documentation/trace/stm.txt
-
-
-Using perf tools
-----------------
+2.1) AutoFDO analysis using the perf tools:
 
 perf can be used to record and analyze trace of programs.
 
@@ -428,3 +393,38 @@ sort example is from the AutoFDO tutorial (https://gcc.gnu.org/wiki/AutoFDO/Tuto
 	$ taskset -c 2 ./sort_autofdo
 	Bubble sorting array of 30000 elements
 	5806 ms
+
+
+How to use the STM module
+-------------------------
+
+Using the System Trace Macrocell module is the same as the tracers - the only
+difference is that clients are driving the trace capture rather
+than the program flow through the code.
+
+As with any other CoreSight component, specifics about the STM tracer can be
+found in sysfs with more information on each entry being found in [1]:
+
+root@genericarmv8:~# ls /sys/bus/coresight/devices/20100000.stm
+enable_source   hwevent_select  port_enable     subsystem       uevent
+hwevent_enable  mgmt            port_select     traceid
+root@genericarmv8:~#
+
+Like any other source a sink needs to be identified and the STM enabled before
+being used:
+
+root@genericarmv8:~# echo 1 > /sys/bus/coresight/devices/20010000.etf/enable_sink
+root@genericarmv8:~# echo 1 > /sys/bus/coresight/devices/20100000.stm/enable_source
+
+From there user space applications can request and use channels using the devfs
+interface provided for that purpose by the generic STM API:
+
+root@genericarmv8:~# ls -l /dev/20100000.stm
+crw-------    1 root     root       10,  61 Jan  3 18:11 /dev/20100000.stm
+root@genericarmv8:~#
+
+Details on how to use the generic STM API can be found here [2].
+
+[1]. Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
+[2]. Documentation/trace/stm.txt
+[3]. https://github.com/Linaro/perf-opencsd