Hi Tran,
Thank you for doing this - it adds much needed consistency to this
file. A few of comments below....
On Fri, 5 Jul 2019 at 14:45, Phong Tran <tranmanphong@xxxxxxxxx> wrote:
>
> change the format file and adpate the text style
This changtelog is a little short and mentions what you are doing
rather than why.
>
> Signed-off-by: Phong Tran <tranmanphong@xxxxxxxxx>
> ---
> .../trace/{coresight.txt => coresight.rst} | 296 ++++++++++++---------
> Documentation/trace/index.rst | 1 +
> 2 files changed, 167 insertions(+), 130 deletions(-)
> rename Documentation/trace/{coresight.txt => coresight.rst} (59%)
File "coresight.txt" is referenced in the MAINTAINERS file and should
probably be changed there as well.
Did you look at coresight-cpu-debug.txt? In my opinion both files
should be changed in the same patchset.
Thanks,
Mathieu
>
> diff --git a/Documentation/trace/coresight.txt b/Documentation/trace/coresight.rst
> similarity index 59%
> rename from Documentation/trace/coresight.txt
> rename to Documentation/trace/coresight.rst
> index efbc832146e7..bea24e70cfba 100644
> --- a/Documentation/trace/coresight.txt
> +++ b/Documentation/trace/coresight.rst
> @@ -1,5 +1,6 @@
> - Coresight - HW Assisted Tracing on ARM
> - ======================================
> +======================================
> +Coresight - HW Assisted Tracing on ARM
> +======================================
>
> Author: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Date: September 11th, 2014
> @@ -26,7 +27,7 @@ implementation, either storing the compressed stream in a memory buffer or
> creating an interface to the outside world where data can be transferred to a
> host without fear of filling up the onboard coresight memory buffer.
>
> -At typical coresight system would look like this:
> +At typical coresight system would look like this::
>
> *****************************************************************
> **************************** AMBA AXI ****************************===||
> @@ -95,6 +96,7 @@ Acronyms and Classification
>
> Acronyms:
>
> +======== =============================================================
> PTM: Program Trace Macrocell
> ETM: Embedded Trace Macrocell
> STM: System trace Macrocell
> @@ -104,6 +106,7 @@ TPIU: Trace Port Interface Unit
> TMC-ETR: Trace Memory Controller, configured as Embedded Trace Router
> TMC-ETF: Trace Memory Controller, configured as Embedded Trace FIFO
> CTI: Cross Trigger Interface
> +======== =============================================================
>
> Classification:
>
> @@ -118,7 +121,7 @@ Misc:
>
>
> Device Tree Bindings
> -----------------------
> +--------------------
>
> See Documentation/devicetree/bindings/arm/coresight.txt for details.
>
> @@ -133,57 +136,63 @@ The coresight framework provides a central point to represent, configure and
> manage coresight devices on a platform. Any coresight compliant device can
> register with the framework for as long as they use the right APIs:
>
> -struct coresight_device *coresight_register(struct coresight_desc *desc);
> -void coresight_unregister(struct coresight_device *csdev);
> +.. c:function:: struct coresight_device *coresight_register(struct coresight_desc *desc);
> +.. c:function:: void coresight_unregister(struct coresight_device *csdev);
>
> -The registering function is taking a "struct coresight_device *csdev" and
> +The registering function is taking a :code:`struct coresight_device *csdev` and
> register the device with the core framework. The unregister function takes
> -a reference to a "struct coresight_device", obtained at registration time.
> +a reference to a :code:`struct coresight_device`, obtained at registration time.
>
> If everything goes well during the registration process the new devices will
> show up under /sys/bus/coresight/devices, as showns here for a TC2 platform:
>
> -root:~# ls /sys/bus/coresight/devices/
> -replicator 20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm
> -20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm
> -root:~#
> +.. code:: console
>
> -The functions take a "struct coresight_device", which looks like this:
> + root:~# ls /sys/bus/coresight/devices/
> + replicator 20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm
> + 20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm
> + root:~#
>
> -struct coresight_desc {
> - enum coresight_dev_type type;
> - struct coresight_dev_subtype subtype;
> - const struct coresight_ops *ops;
> - struct coresight_platform_data *pdata;
> - struct device *dev;
> - const struct attribute_group **groups;
> -};
> +The functions take a :code:`struct coresight_device`, which looks like this:
> +
> +.. code:: c
> +
> + struct coresight_desc {
> + enum coresight_dev_type type;
> + struct coresight_dev_subtype subtype;
> + const struct coresight_ops *ops;
> + struct coresight_platform_data *pdata;
> + struct device *dev;
> + const struct attribute_group **groups;
> + };
>
>
> The "coresight_dev_type" identifies what the device is, i.e, source link or
> sink while the "coresight_dev_subtype" will characterise that type further.
>
> -The "struct coresight_ops" is mandatory and will tell the framework how to
> +The :code:`struct coresight_ops` is mandatory and will tell the framework how to
> perform base operations related to the components, each component having
> -a different set of requirement. For that "struct coresight_ops_sink",
> -"struct coresight_ops_link" and "struct coresight_ops_source" have been
> +a different set of requirement. For that :code:`struct coresight_ops_sink,
> +struct coresight_ops_link` and :code:`struct coresight_ops_source` have been
> provided.
>
> -The next field, "struct coresight_platform_data *pdata" is acquired by calling
> -"of_get_coresight_platform_data()", as part of the driver's _probe routine and
> -"struct device *dev" gets the device reference embedded in the "amba_device":
> +The next field, :code:`struct coresight_platform_data *pdata` is acquired by calling
> +:code:`of_get_coresight_platform_data()`, as part of the driver's _probe routine and
> +:code:`struct device *dev` gets the device reference embedded in the :code:`amba_device`:
>
> -static int etm_probe(struct amba_device *adev, const struct amba_id *id)
> -{
> - ...
> - ...
> - drvdata->dev = &adev->dev;
> - ...
> -}
> +.. code:: c
> +
> + static int etm_probe(struct amba_device *adev, const struct amba_id *id)
> + {
> + ...
> + ...
> + drvdata->dev = &adev->dev;
> + ...
> + }
>
> Specific class of device (source, link, or sink) have generic operations
> -that can be performed on them (see "struct coresight_ops"). The
> -"**groups" is a list of sysfs entries pertaining to operations
> +that can be performed on them (see :code:`struct coresight_ops`). The
> +:code:`**groups` is a list of sysfs entries pertaining to operations
> specific to that component only. "Implementation defined" customisations are
> expected to be accessed and controlled using those entries.
>
> @@ -204,49 +213,56 @@ There is no limit on the amount of sinks (nor sources) that can be enabled at
> any given moment. As a generic operation, all device pertaining to the sink
> class will have an "active" entry in sysfs:
>
> -root:/sys/bus/coresight/devices# ls
> -replicator 20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm
> -20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm
> -root:/sys/bus/coresight/devices# ls 20010000.etb
> -enable_sink status trigger_cntr
> -root:/sys/bus/coresight/devices# echo 1 > 20010000.etb/enable_sink
> -root:/sys/bus/coresight/devices# cat 20010000.etb/enable_sink
> -1
> -root:/sys/bus/coresight/devices#
> +.. code:: console
> +
> + root:/sys/bus/coresight/devices# ls
> + replicator 20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm
> + 20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm
> + root:/sys/bus/coresight/devices# ls 20010000.etb
> + enable_sink status trigger_cntr
> + root:/sys/bus/coresight/devices# echo 1 > 20010000.etb/enable_sink
> + root:/sys/bus/coresight/devices# cat 20010000.etb/enable_sink
> + 1
> + root:/sys/bus/coresight/devices#
>
> At boot time the current etm3x driver will configure the first address
> comparator with "_stext" and "_etext", essentially tracing any instruction
> that falls within that range. As such "enabling" a source will immediately
> trigger a trace capture:
>
> -root:/sys/bus/coresight/devices# echo 1 > 2201c000.ptm/enable_source
> -root:/sys/bus/coresight/devices# cat 2201c000.ptm/enable_source
> -1
> -root:/sys/bus/coresight/devices# cat 20010000.etb/status
> -Depth: 0x2000
> -Status: 0x1
> -RAM read ptr: 0x0
> -RAM wrt ptr: 0x19d3 <----- The write pointer is moving
> -Trigger cnt: 0x0
> -Control: 0x1
> -Flush status: 0x0
> -Flush ctrl: 0x2001
> -root:/sys/bus/coresight/devices#
> +.. code:: console
> +
> + root:/sys/bus/coresight/devices# echo 1 > 2201c000.ptm/enable_source
> + root:/sys/bus/coresight/devices# cat 2201c000.ptm/enable_source
> + 1
> + root:/sys/bus/coresight/devices# cat 20010000.etb/status
> + Depth: 0x2000
> + Status: 0x1
> + RAM read ptr: 0x0
> + RAM wrt ptr: 0x19d3 <----- The write pointer is moving
> + Trigger cnt: 0x0
> + Control: 0x1
> + Flush status: 0x0
> + Flush ctrl: 0x2001
> + root:/sys/bus/coresight/devices#
>
> Trace collection is stopped the same way:
>
> -root:/sys/bus/coresight/devices# echo 0 > 2201c000.ptm/enable_source
> -root:/sys/bus/coresight/devices#
> +.. code:: console
> +
> + root:/sys/bus/coresight/devices# echo 0 > 2201c000.ptm/enable_source
> + root:/sys/bus/coresight/devices#
>
> The content of the ETB buffer can be harvested directly from /dev:
>
> -root:/sys/bus/coresight/devices# dd if=/dev/20010000.etb \
> -of=~/cstrace.bin
> +.. code:: console
>
> -64+0 records in
> -64+0 records out
> -32768 bytes (33 kB) copied, 0.00125258 s, 26.2 MB/s
> -root:/sys/bus/coresight/devices#
> + root:/sys/bus/coresight/devices# dd if=/dev/20010000.etb \
> + of=~/cstrace.bin
> + 64+0 records in
> + 64+0 records out
> + 32768 bytes (33 kB) copied, 0.00125258 s, 26.2 MB/s
> + root:/sys/bus/coresight/devices#
>
> The file cstrace.bin can be decompressed using "ptm2human", DS-5 or Trace32.
>
> @@ -254,55 +270,57 @@ Following is a DS-5 output of an experimental loop that increments a variable up
> to a certain value. The example is simple and yet provides a glimpse of the
> wealth of possibilities that coresight provides.
>
> -Info Tracing enabled
> -Instruction 106378866 0x8026B53C E52DE004 false PUSH {lr}
> -Instruction 0 0x8026B540 E24DD00C false SUB sp,sp,#0xc
> -Instruction 0 0x8026B544 E3A03000 false MOV r3,#0
> -Instruction 0 0x8026B548 E58D3004 false STR r3,[sp,#4]
> -Instruction 0 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> -Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> -Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> -Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> -Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> -Timestamp Timestamp: 17106715833
> -Instruction 319 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> -Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> -Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> -Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> -Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> -Instruction 9 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> -Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> -Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> -Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> -Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> -Instruction 7 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> -Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> -Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> -Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> -Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> -Instruction 7 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> -Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> -Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> -Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> -Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> -Instruction 10 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> -Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> -Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> -Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> -Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> -Instruction 6 0x8026B560 EE1D3F30 false MRC p15,#0x0,r3,c13,c0,#1
> -Instruction 0 0x8026B564 E1A0100D false MOV r1,sp
> -Instruction 0 0x8026B568 E3C12D7F false BIC r2,r1,#0x1fc0
> -Instruction 0 0x8026B56C E3C2203F false BIC r2,r2,#0x3f
> -Instruction 0 0x8026B570 E59D1004 false LDR r1,[sp,#4]
> -Instruction 0 0x8026B574 E59F0010 false LDR r0,[pc,#16] ; [0x8026B58C] = 0x80550368
> -Instruction 0 0x8026B578 E592200C false LDR r2,[r2,#0xc]
> -Instruction 0 0x8026B57C E59221D0 false LDR r2,[r2,#0x1d0]
> -Instruction 0 0x8026B580 EB07A4CF true BL {pc}+0x1e9344 ; 0x804548c4
> -Info Tracing enabled
> -Instruction 13570831 0x8026B584 E28DD00C false ADD sp,sp,#0xc
> -Instruction 0 0x8026B588 E8BD8000 true LDM sp!,{pc}
> -Timestamp Timestamp: 17107041535
> +.. code:: c
> +
> + Info Tracing enabled
> + Instruction 106378866 0x8026B53C E52DE004 false PUSH {lr}
> + Instruction 0 0x8026B540 E24DD00C false SUB sp,sp,#0xc
> + Instruction 0 0x8026B544 E3A03000 false MOV r3,#0
> + Instruction 0 0x8026B548 E58D3004 false STR r3,[sp,#4]
> + Instruction 0 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> + Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> + Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> + Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> + Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> + Timestamp Timestamp: 17106715833
> + Instruction 319 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> + Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> + Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> + Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> + Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> + Instruction 9 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> + Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> + Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> + Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> + Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> + Instruction 7 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> + Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> + Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> + Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> + Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> + Instruction 7 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> + Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> + Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> + Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> + Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> + Instruction 10 0x8026B54C E59D3004 false LDR r3,[sp,#4]
> + Instruction 0 0x8026B550 E3530004 false CMP r3,#4
> + Instruction 0 0x8026B554 E2833001 false ADD r3,r3,#1
> + Instruction 0 0x8026B558 E58D3004 false STR r3,[sp,#4]
> + Instruction 0 0x8026B55C DAFFFFFA true BLE {pc}-0x10 ; 0x8026b54c
> + Instruction 6 0x8026B560 EE1D3F30 false MRC p15,#0x0,r3,c13,c0,#1
> + Instruction 0 0x8026B564 E1A0100D false MOV r1,sp
> + Instruction 0 0x8026B568 E3C12D7F false BIC r2,r1,#0x1fc0
> + Instruction 0 0x8026B56C E3C2203F false BIC r2,r2,#0x3f
> + Instruction 0 0x8026B570 E59D1004 false LDR r1,[sp,#4]
> + Instruction 0 0x8026B574 E59F0010 false LDR r0,[pc,#16] ; [0x8026B58C] = 0x80550368
> + Instruction 0 0x8026B578 E592200C false LDR r2,[r2,#0xc]
> + Instruction 0 0x8026B57C E59221D0 false LDR r2,[r2,#0x1d0]
> + Instruction 0 0x8026B580 EB07A4CF true BL {pc}+0x1e9344 ; 0x804548c4
> + Info Tracing enabled
> + Instruction 13570831 0x8026B584 E28DD00C false ADD sp,sp,#0xc
> + Instruction 0 0x8026B588 E8BD8000 true LDM sp!,{pc}
> + Timestamp Timestamp: 17107041535
>
> 2) Using perf framework:
>
> @@ -312,6 +330,8 @@ controlling when tracing gets enabled based on when the process of interest is
> scheduled. When configured in a system, Coresight PMUs will be listed when
> queried by the perf command line tool:
>
> +.. code:: console
> +
> linaro@linaro-nano:~$ ./perf list pmu
>
> List of pre-defined events (to be used in -e):
> @@ -329,6 +349,8 @@ Coresight system will typically have more than one sink, the name of the sink to
> work with needs to be specified as an event option. Names for sink to choose
> from are listed in sysFS under ($SYSFS)/bus/coresight/devices:
>
> +.. code:: console
> +
> root@linaro-nano:~# ls /sys/bus/coresight/devices/
> 20010000.etf 20040000.funnel 20100000.stm 22040000.etm
> 22140000.etm 230c0000.funnel 23240000.etm 20030000.tpiu
> @@ -343,7 +365,7 @@ to use for the trace session.
>
> 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].
> +repository [#third]_.
>
> 2.1) AutoFDO analysis using the perf tools:
>
> @@ -352,6 +374,8 @@ perf can be used to record and analyze trace of programs.
> Execution can be recorded using 'perf record' with the cs_etm event,
> specifying the name of the sink to record to, e.g:
>
> +.. code:: console
> +
> perf record -e cs_etm/@20070000.etr/u --per-thread
>
> The 'perf report' and 'perf script' commands can be used to analyze execution,
> @@ -370,12 +394,16 @@ Generating coverage files for Feedback Directed Optimization: AutoFDO
> 'perf inject' accepts the --itrace option in which case tracing data is
> removed and replaced with the synthesized events. e.g.
>
> +.. code:: console
> +
> perf inject --itrace --strip -i perf.data -o perf.data.new
>
> Below is an example of using ARM ETM for autoFDO. It requires autofdo
> (https://github.com/google/autofdo) and gcc version 5. The bubble
> sort example is from the AutoFDO tutorial (https://gcc.gnu.org/wiki/AutoFDO/Tutorial).
>
> +.. code:: console
> +
> $ gcc-5 -O3 sort.c -o sort
> $ taskset -c 2 ./sort
> Bubble sorting array of 30000 elements
> @@ -403,28 +431,36 @@ 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]:
> +found in sysfs with more information on each entry being found in [#first]_:
>
> -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:~#
> +.. code:: console
> +
> + 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
> +.. code:: console
> +
> + 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:~#
> +.. code:: console
> +
> + 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 [#second]_.
> +
> +.. [#first] Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
>
> -Details on how to use the generic STM API can be found here [2].
> +.. [#second] Documentation/trace/stm.rst
>
> -[1]. Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
> -[2]. Documentation/trace/stm.rst
> -[3]. https://github.com/Linaro/perf-opencsd
> +.. [#third] https://github.com/Linaro/perf-opencsd
> diff --git a/Documentation/trace/index.rst b/Documentation/trace/index.rst
> index 6b4107cf4b98..3330c5456bcb 100644
> --- a/Documentation/trace/index.rst
> +++ b/Documentation/trace/index.rst
> @@ -23,3 +23,4 @@ Linux Tracing Technologies
> intel_th
> stm
> sys-t
> + coresight
> --
> 2.11.0
>
