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| author |   Joakim Zhang <qiangqing.zhang@nxp.com> | 2019-11-04 07:09:20 +0000 |
|---|---|---|
| committer |   Will Deacon <will@kernel.org> | 2019-11-04 16:27:34 +0000 |
| commit | ed0207a33adda11db88c9c3b6066f0c6051119fe (patch) | |
| tree | ff940b0c1e1081211519162d81d3e7a348679271 /Documentation | |
| parent | perf/imx_ddr: Add driver for DDR PMU in i.MX8MPlus (diff) | |
| download | linux-dev-ed0207a33adda11db88c9c3b6066f0c6051119fe.tar.xz linux-dev-ed0207a33adda11db88c9c3b6066f0c6051119fe.zip | |
docs/perf: Add AXI ID filter capabilities information
Add capabilities information for AXI ID filter.
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/perf/imx-ddr.rst | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/Documentation/admin-guide/perf/imx-ddr.rst b/Documentation/admin-guide/perf/imx-ddr.rst index 66988b481217..90056e4e8859 100644 --- a/Documentation/admin-guide/perf/imx-ddr.rst +++ b/Documentation/admin-guide/perf/imx-ddr.rst @@ -17,7 +17,8 @@ The "format" directory describes format of the config (event ID) and config1 (AXI filtering) fields of the perf_event_attr structure, see /sys/bus/event_source/ 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/. +devices/imx8_ddr0/events/. The "caps" directory describes filter features implemented +in DDR PMU, see /sys/bus/events_source/devices/imx8_ddr0/caps/. e.g.:: perf stat -a -e imx8_ddr0/cycles/ cmd perf stat -a -e imx8_ddr0/read/,imx8_ddr0/write/ cmd @@ -25,9 +26,12 @@ devices/imx8_ddr0/events/. AXI filtering is only used by CSV modes 0x41 (axid-read) and 0x42 (axid-write) to count reading or writing matches filter setting. Filter setting is various from different DRAM controller implementations, which is distinguished by quirks -in the driver. +in the driver. You also can dump info from userspace, filter in "caps" directory +indicates whether PMU supports AXI ID filter or not; enhanced_filter indicates +whether PMU supports enhanced AXI ID filter or not. Value 0 for un-supported, and +value 1 for supported. -* With DDR_CAP_AXI_ID_FILTER quirk. +* With DDR_CAP_AXI_ID_FILTER quirk(filter: 1, enhanced_filter: 0). 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. @@ -51,7 +55,7 @@ in the driver. e.g.:: perf stat -a -e imx8_ddr0/axid-read,axi_id=0x12/ cmd, which will monitor ARID=0x12 -* With DDR_CAP_AXI_ID_FILTER_ENHANCED quirk. +* With DDR_CAP_AXI_ID_FILTER_ENHANCED quirk(filter: 1, enhanced_filter: 1). This is an extension to the DDR_CAP_AXI_ID_FILTER quirk which permits counting the number of bytes (as opposed to the number of bursts) from DDR read and write transactions concurrently with another set of data counters. |