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PCIe PMU Root Complex Integrated End Point(RCiEP) device is supported on HiSilicon HIP09 platform. Document it to provide guidance on how to use it. Reviewed-by: John Garry <john.garry@huawei.com> Signed-off-by: Qi Liu <liuqi115@huawei.com> Reviewed-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Link: https://lore.kernel.org/r/20211202080633.2919-2-liuqi115@huawei.com Signed-off-by: Will Deacon <will@kernel.org>
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3.8 KiB
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106 lines
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HiSilicon PCIe Performance Monitoring Unit (PMU)
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================================================
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On Hip09, HiSilicon PCIe Performance Monitoring Unit (PMU) could monitor
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bandwidth, latency, bus utilization and buffer occupancy data of PCIe.
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Each PCIe Core has a PMU to monitor multi Root Ports of this PCIe Core and
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all Endpoints downstream these Root Ports.
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HiSilicon PCIe PMU driver
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=========================
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The PCIe PMU driver registers a perf PMU with the name of its sicl-id and PCIe
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Core id.::
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/sys/bus/event_source/hisi_pcie<sicl>_<core>
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PMU driver provides description of available events and filter options in sysfs,
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see /sys/bus/event_source/devices/hisi_pcie<sicl>_<core>.
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The "format" directory describes all formats of the config (events) and config1
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(filter options) fields of the perf_event_attr structure. The "events" directory
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describes all documented events shown in perf list.
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The "identifier" sysfs file allows users to identify the version of the
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PMU hardware device.
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The "bus" sysfs file allows users to get the bus number of Root Ports
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monitored by PMU.
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Example usage of perf::
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$# perf list
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hisi_pcie0_0/rx_mwr_latency/ [kernel PMU event]
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hisi_pcie0_0/rx_mwr_cnt/ [kernel PMU event]
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------------------------------------------
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$# perf stat -e hisi_pcie0_0/rx_mwr_latency/
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$# perf stat -e hisi_pcie0_0/rx_mwr_cnt/
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$# perf stat -g -e hisi_pcie0_0/rx_mwr_latency/ -e hisi_pcie0_0/rx_mwr_cnt/
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The current driver does not support sampling. So "perf record" is unsupported.
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Also attach to a task is unsupported for PCIe PMU.
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Filter options
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--------------
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1. Target filter
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PMU could only monitor the performance of traffic downstream target Root Ports
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or downstream target Endpoint. PCIe PMU driver support "port" and "bdf"
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interfaces for users, and these two interfaces aren't supported at the same
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time.
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-port
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"port" filter can be used in all PCIe PMU events, target Root Port can be
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selected by configuring the 16-bits-bitmap "port". Multi ports can be selected
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for AP-layer-events, and only one port can be selected for TL/DL-layer-events.
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For example, if target Root Port is 0000:00:00.0 (x8 lanes), bit0 of bitmap
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should be set, port=0x1; if target Root Port is 0000:00:04.0 (x4 lanes),
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bit8 is set, port=0x100; if these two Root Ports are both monitored, port=0x101.
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Example usage of perf::
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$# perf stat -e hisi_pcie0_0/rx_mwr_latency,port=0x1/ sleep 5
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-bdf
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"bdf" filter can only be used in bandwidth events, target Endpoint is selected
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by configuring BDF to "bdf". Counter only counts the bandwidth of message
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requested by target Endpoint.
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For example, "bdf=0x3900" means BDF of target Endpoint is 0000:39:00.0.
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Example usage of perf::
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$# perf stat -e hisi_pcie0_0/rx_mrd_flux,bdf=0x3900/ sleep 5
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2. Trigger filter
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Event statistics start when the first time TLP length is greater/smaller
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than trigger condition. You can set the trigger condition by writing "trig_len",
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and set the trigger mode by writing "trig_mode". This filter can only be used
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in bandwidth events.
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For example, "trig_len=4" means trigger condition is 2^4 DW, "trig_mode=0"
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means statistics start when TLP length > trigger condition, "trig_mode=1"
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means start when TLP length < condition.
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Example usage of perf::
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$# perf stat -e hisi_pcie0_0/rx_mrd_flux,trig_len=0x4,trig_mode=1/ sleep 5
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3. Threshold filter
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Counter counts when TLP length within the specified range. You can set the
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threshold by writing "thr_len", and set the threshold mode by writing
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"thr_mode". This filter can only be used in bandwidth events.
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For example, "thr_len=4" means threshold is 2^4 DW, "thr_mode=0" means
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counter counts when TLP length >= threshold, and "thr_mode=1" means counts
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when TLP length < threshold.
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Example usage of perf::
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$# perf stat -e hisi_pcie0_0/rx_mrd_flux,thr_len=0x4,thr_mode=1/ sleep 5
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