| Message ID | 20180507172915.c032cd71c07b1849bf419a5f@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 7 May 2018 at 16:29, Kim Phillips <kim.phillips@arm.com> wrote: > - Align and show updated ls devices output from the TC2, based on > current driver > > - Provide an example from an ETMv4 based system (Juno) > > - Reflect changes to the way the RAM write pointer is accessed since > it got changed in commit 7d83d17795ef ("coresight: tmc: adding sysFS > management entries"). > > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Jonathan Corbet <corbet@lwn.net> > Signed-off-by: Kim Phillips <kim.phillips@arm.com> > --- > Documentation/trace/coresight.txt | 40 ++++++++++++++++++------------- > 1 file changed, 24 insertions(+), 16 deletions(-) > > diff --git a/Documentation/trace/coresight.txt b/Documentation/trace/coresight.txt > index 6f0120c3a4f1..d23d6354b372 100644 > --- a/Documentation/trace/coresight.txt > +++ b/Documentation/trace/coresight.txt > @@ -144,10 +144,21 @@ 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 > +20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm replicator > +20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm > root:~# > > +and here for a Juno platform: > + > +root@juno:~# ls /sys/bus/coresight/devices/ > +20010000.etf 20120000.replicator 22040000.etm 230c0000.funnel > +20030000.tpiu 20130000.funnel 220c0000.funnel 23140000.etm > +20040000.funnel 20140000.etf 22140000.etm 23240000.etm > +20070000.etr 20150000.funnel 23040000.etm 23340000.etm > +root@juno:~# > + > +Note the Juno uses an Embedded Trace Router (ETR) instead of an ETB. The above is not entirely correct. On Juno users can select the ETF, ETR and TPIU as a sink target while on TC2, the ETB and TPIU can be selected. > + > The functions take a "struct coresight_device", which looks like this: > > struct coresight_desc { > @@ -193,16 +204,16 @@ the information carried in "THIS_MODULE". > How to use the tracer modules > ----------------------------- > > -Before trace collection can start, a coresight sink needs to be identify. > +Before trace collection can start, a coresight sink needs to be identified. > 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 > +20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm replicator > +20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm > root:/sys/bus/coresight/devices# ls 20010000.etb > -enable_sink status trigger_cntr > +enable_sink mgmt power subsystem trigger_cntr uevent > root:/sys/bus/coresight/devices# echo 1 > 20010000.etb/enable_sink > root:/sys/bus/coresight/devices# cat 20010000.etb/enable_sink > 1 > @@ -216,16 +227,13 @@ 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# > + > +Observe the write pointer moving: > + > +root:/sys/bus/coresight/devices# cat 20010000.etb/mgmt/rwp > +0x1a8 > +root:/sys/bus/coresight/devices# cat 20010000.etb/mgmt/rwp > +0x19a6 > > Trace collection is stopped the same way: > > -- > 2.17.0 >
diff --git a/Documentation/trace/coresight.txt b/Documentation/trace/coresight.txt index 6f0120c3a4f1..d23d6354b372 100644 --- a/Documentation/trace/coresight.txt +++ b/Documentation/trace/coresight.txt @@ -144,10 +144,21 @@ 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 +20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm replicator +20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm root:~# +and here for a Juno platform: + +root@juno:~# ls /sys/bus/coresight/devices/ +20010000.etf 20120000.replicator 22040000.etm 230c0000.funnel +20030000.tpiu 20130000.funnel 220c0000.funnel 23140000.etm +20040000.funnel 20140000.etf 22140000.etm 23240000.etm +20070000.etr 20150000.funnel 23040000.etm 23340000.etm +root@juno:~# + +Note the Juno uses an Embedded Trace Router (ETR) instead of an ETB. + The functions take a "struct coresight_device", which looks like this: struct coresight_desc { @@ -193,16 +204,16 @@ the information carried in "THIS_MODULE". How to use the tracer modules ----------------------------- -Before trace collection can start, a coresight sink needs to be identify. +Before trace collection can start, a coresight sink needs to be identified. 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 +20010000.etb 20040000.funnel 2201d000.ptm 2203d000.etm replicator +20030000.tpiu 2201c000.ptm 2203c000.etm 2203e000.etm root:/sys/bus/coresight/devices# ls 20010000.etb -enable_sink status trigger_cntr +enable_sink mgmt power subsystem trigger_cntr uevent root:/sys/bus/coresight/devices# echo 1 > 20010000.etb/enable_sink root:/sys/bus/coresight/devices# cat 20010000.etb/enable_sink 1 @@ -216,16 +227,13 @@ 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# + +Observe the write pointer moving: + +root:/sys/bus/coresight/devices# cat 20010000.etb/mgmt/rwp +0x1a8 +root:/sys/bus/coresight/devices# cat 20010000.etb/mgmt/rwp +0x19a6 Trace collection is stopped the same way:
- Align and show updated ls devices output from the TC2, based on current driver - Provide an example from an ETMv4 based system (Juno) - Reflect changes to the way the RAM write pointer is accessed since it got changed in commit 7d83d17795ef ("coresight: tmc: adding sysFS management entries"). Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Kim Phillips <kim.phillips@arm.com> --- Documentation/trace/coresight.txt | 40 ++++++++++++++++++------------- 1 file changed, 24 insertions(+), 16 deletions(-)