Commit fe13225f authored by Phong Tran's avatar Phong Tran Committed by Jonathan Corbet

Documentation: coresight: convert txt to rst

This changes from plain text to reStructuredText as suggestion
in doc-guide [1]

[1] https://www.kernel.org/doc/html/latest/doc-guide/sphinx.html

Some adaptations such as: literal block, ``inline literal`` and
alignment text,...
Signed-off-by: default avatarPhong Tran <tranmanphong@gmail.com>
Reviewed-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 34d5f4f2
Coresight CPU Debug Module ==========================
========================== Coresight CPU Debug Module
==========================
Author: Leo Yan <leo.yan@linaro.org> :Author: Leo Yan <leo.yan@linaro.org>
Date: April 5th, 2017 :Date: April 5th, 2017
Introduction Introduction
------------ ------------
...@@ -69,6 +70,7 @@ Before accessing debug registers, we should ensure the clock and power domain ...@@ -69,6 +70,7 @@ Before accessing debug registers, we should ensure the clock and power domain
have been enabled properly. In ARMv8-a ARM (ARM DDI 0487A.k) chapter 'H9.1 have been enabled properly. In ARMv8-a ARM (ARM DDI 0487A.k) chapter 'H9.1
Debug registers', the debug registers are spread into two domains: the debug Debug registers', the debug registers are spread into two domains: the debug
domain and the CPU domain. domain and the CPU domain.
::
+---------------+ +---------------+
| | | |
...@@ -125,18 +127,21 @@ If you want to enable debugging functionality at boot time, you can add ...@@ -125,18 +127,21 @@ If you want to enable debugging functionality at boot time, you can add
"coresight_cpu_debug.enable=1" to the kernel command line parameter. "coresight_cpu_debug.enable=1" to the kernel command line parameter.
The driver also can work as module, so can enable the debugging when insmod The driver also can work as module, so can enable the debugging when insmod
module: module::
# insmod coresight_cpu_debug.ko debug=1
# insmod coresight_cpu_debug.ko debug=1
When boot time or insmod module you have not enabled the debugging, the driver When boot time or insmod module you have not enabled the debugging, the driver
uses the debugfs file system to provide a knob to dynamically enable or disable uses the debugfs file system to provide a knob to dynamically enable or disable
debugging: debugging:
To enable it, write a '1' into /sys/kernel/debug/coresight_cpu_debug/enable: To enable it, write a '1' into /sys/kernel/debug/coresight_cpu_debug/enable::
# echo 1 > /sys/kernel/debug/coresight_cpu_debug/enable
# echo 1 > /sys/kernel/debug/coresight_cpu_debug/enable
To disable it, write a '0' into /sys/kernel/debug/coresight_cpu_debug/enable::
To disable it, write a '0' into /sys/kernel/debug/coresight_cpu_debug/enable: # echo 0 > /sys/kernel/debug/coresight_cpu_debug/enable
# echo 0 > /sys/kernel/debug/coresight_cpu_debug/enable
As explained in chapter "Clock and power domain", if you are working on one As explained in chapter "Clock and power domain", if you are working on one
platform which has idle states to power off debug logic and the power platform which has idle states to power off debug logic and the power
...@@ -154,34 +159,34 @@ subsystem, more specifically by using the "/dev/cpu_dma_latency" ...@@ -154,34 +159,34 @@ subsystem, more specifically by using the "/dev/cpu_dma_latency"
interface (see Documentation/power/pm_qos_interface.rst for more interface (see Documentation/power/pm_qos_interface.rst for more
details). As specified in the PM QoS documentation the requested details). As specified in the PM QoS documentation the requested
parameter will stay in effect until the file descriptor is released. parameter will stay in effect until the file descriptor is released.
For example: For example::
# exec 3<> /dev/cpu_dma_latency; echo 0 >&3 # exec 3<> /dev/cpu_dma_latency; echo 0 >&3
... ...
Do some work... Do some work...
... ...
# exec 3<>- # exec 3<>-
The same can also be done from an application program. The same can also be done from an application program.
Disable specific CPU's specific idle state from cpuidle sysfs (see Disable specific CPU's specific idle state from cpuidle sysfs (see
Documentation/admin-guide/pm/cpuidle.rst): Documentation/admin-guide/pm/cpuidle.rst)::
# echo 1 > /sys/devices/system/cpu/cpu$cpu/cpuidle/state$state/disable
# echo 1 > /sys/devices/system/cpu/cpu$cpu/cpuidle/state$state/disable
Output format Output format
------------- -------------
Here is an example of the debugging output format: Here is an example of the debugging output format::
ARM external debug module: ARM external debug module:
coresight-cpu-debug 850000.debug: CPU[0]: coresight-cpu-debug 850000.debug: CPU[0]:
coresight-cpu-debug 850000.debug: EDPRSR: 00000001 (Power:On DLK:Unlock) coresight-cpu-debug 850000.debug: EDPRSR: 00000001 (Power:On DLK:Unlock)
coresight-cpu-debug 850000.debug: EDPCSR: handle_IPI+0x174/0x1d8 coresight-cpu-debug 850000.debug: EDPCSR: handle_IPI+0x174/0x1d8
coresight-cpu-debug 850000.debug: EDCIDSR: 00000000 coresight-cpu-debug 850000.debug: EDCIDSR: 00000000
coresight-cpu-debug 850000.debug: EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0) coresight-cpu-debug 850000.debug: EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0)
coresight-cpu-debug 852000.debug: CPU[1]: coresight-cpu-debug 852000.debug: CPU[1]:
coresight-cpu-debug 852000.debug: EDPRSR: 00000001 (Power:On DLK:Unlock) coresight-cpu-debug 852000.debug: EDPRSR: 00000001 (Power:On DLK:Unlock)
coresight-cpu-debug 852000.debug: EDPCSR: debug_notifier_call+0x23c/0x358 coresight-cpu-debug 852000.debug: EDPCSR: debug_notifier_call+0x23c/0x358
coresight-cpu-debug 852000.debug: EDCIDSR: 00000000 coresight-cpu-debug 852000.debug: EDCIDSR: 00000000
coresight-cpu-debug 852000.debug: EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0) coresight-cpu-debug 852000.debug: EDVIDSR: 90000000 (State:Non-secure Mode:EL1/0 Width:64bits VMID:0)
...@@ -23,3 +23,5 @@ Linux Tracing Technologies ...@@ -23,3 +23,5 @@ Linux Tracing Technologies
intel_th intel_th
stm stm
sys-t sys-t
coresight
coresight-cpu-debug
...@@ -1582,8 +1582,8 @@ R: Suzuki K Poulose <suzuki.poulose@arm.com> ...@@ -1582,8 +1582,8 @@ R: Suzuki K Poulose <suzuki.poulose@arm.com>
L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
S: Maintained S: Maintained
F: drivers/hwtracing/coresight/* F: drivers/hwtracing/coresight/*
F: Documentation/trace/coresight.txt F: Documentation/trace/coresight.rst
F: Documentation/trace/coresight-cpu-debug.txt F: Documentation/trace/coresight-cpu-debug.rst
F: Documentation/devicetree/bindings/arm/coresight.txt F: Documentation/devicetree/bindings/arm/coresight.txt
F: Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt F: Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt
F: Documentation/ABI/testing/sysfs-bus-coresight-devices-* F: Documentation/ABI/testing/sysfs-bus-coresight-devices-*
......
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