Commit 0522e130 authored by Adam Zerella's avatar Adam Zerella Committed by Jonathan Corbet

docs: perf: Add imx-ddr to documentation index

Sphinx is currently outputting a warning where
the file 'imx-ddr.rst' is not included in the
documentation index. Additionally, the code
highlighting and doc formatting can be slightly
improved.
Signed-off-by: default avatarAdam Zerella <adam.zerella@gmail.com>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 81929718
......@@ -18,7 +18,9 @@ The "format" directory describes format of the config (event ID) and config1
devices/imx8_ddr0/format/. The "events" directory describes the events types
hardware supported that can be used with perf tool, see /sys/bus/event_source/
devices/imx8_ddr0/events/.
e.g.::
.. code-block:: bash
perf stat -a -e imx8_ddr0/cycles/ cmd
perf stat -a -e imx8_ddr0/read/,imx8_ddr0/write/ cmd
......@@ -31,22 +33,29 @@ in the driver.
Filter is defined with two configuration parts:
--AXI_ID defines AxID matching value.
--AXI_MASKING defines which bits of AxID are meaningful for the matching.
0:corresponding bit is masked.
1: corresponding bit is not masked, i.e. used to do the matching.
- 0: corresponding bit is masked.
- 1: corresponding bit is not masked, i.e. used to do the matching.
AXI_ID and AXI_MASKING are mapped on DPCR1 register in performance counter.
When non-masked bits are matching corresponding AXI_ID bits then counter is
incremented. Perf counter is incremented if
AxID && AXI_MASKING == AXI_ID && AXI_MASKING
AxID && AXI_MASKING == AXI_ID && AXI_MASKING
This filter doesn't support filter different AXI ID for axid-read and axid-write
event at the same time as this filter is shared between counters.
e.g.::
perf stat -a -e imx8_ddr0/axid-read,axi_mask=0xMMMM,axi_id=0xDDDD/ cmd
perf stat -a -e imx8_ddr0/axid-write,axi_mask=0xMMMM,axi_id=0xDDDD/ cmd
NOTE: axi_mask is inverted in userspace(i.e. set bits are bits to mask), and
it will be reverted in driver automatically. so that the user can just specify
axi_id to monitor a specific id, rather than having to specify axi_mask.
e.g.::
perf stat -a -e imx8_ddr0/axid-read,axi_id=0x12/ cmd, which will monitor ARID=0x12
.. code-block:: bash
perf stat -a -e imx8_ddr0/axid-read,axi_mask=0xMMMM,axi_id=0xDDDD/ cmd
perf stat -a -e imx8_ddr0/axid-write,axi_mask=0xMMMM,axi_id=0xDDDD/ cmd
.. note::
axi_mask is inverted in userspace(i.e. set bits are bits to mask), and
it will be reverted in driver automatically. so that the user can just specify
axi_id to monitor a specific id, rather than having to specify axi_mask.
.. code-block:: bash
perf stat -a -e imx8_ddr0/axid-read,axi_id=0x12/ cmd, which will monitor ARID=0x12
......@@ -8,6 +8,7 @@ Performance monitor support
:maxdepth: 1
hisi-pmu
imx-ddr
qcom_l2_pmu
qcom_l3_pmu
arm-ccn
......
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