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diff --git a/Documentation/admin-guide/perf/hisi-pcie-pmu.rst b/Documentation/admin-guide/perf/hisi-pcie-pmu.rst new file mode 100644 index 000000000000..5541ff40e06a --- /dev/null +++ b/Documentation/admin-guide/perf/hisi-pcie-pmu.rst @@ -0,0 +1,146 @@ +================================================ +HiSilicon PCIe Performance Monitoring Unit (PMU) +================================================ + +On Hip09, HiSilicon PCIe Performance Monitoring Unit (PMU) could monitor +bandwidth, latency, bus utilization and buffer occupancy data of PCIe. + +Each PCIe Core has a PMU to monitor multi Root Ports of this PCIe Core and +all Endpoints downstream these Root Ports. + + +HiSilicon PCIe PMU driver +========================= + +The PCIe PMU driver registers a perf PMU with the name of its sicl-id and PCIe +Core id.:: + + /sys/bus/event_source/hisi_pcie<sicl>_core<core> + +PMU driver provides description of available events and filter options in sysfs, +see /sys/bus/event_source/devices/hisi_pcie<sicl>_core<core>. + +The "format" directory describes all formats of the config (events) and config1 +(filter options) fields of the perf_event_attr structure. The "events" directory +describes all documented events shown in perf list. + +The "identifier" sysfs file allows users to identify the version of the +PMU hardware device. + +The "bus" sysfs file allows users to get the bus number of Root Ports +monitored by PMU. + +Example usage of perf:: + + $# perf list + hisi_pcie0_core0/rx_mwr_latency/ [kernel PMU event] + hisi_pcie0_core0/rx_mwr_cnt/ [kernel PMU event] + ------------------------------------------ + + $# perf stat -e hisi_pcie0_core0/rx_mwr_latency,port=0xffff/ + $# perf stat -e hisi_pcie0_core0/rx_mwr_cnt,port=0xffff/ + +The related events usually used to calculate the bandwidth, latency or others. +They need to start and end counting at the same time, therefore related events +are best used in the same event group to get the expected value. There are two +ways to know if they are related events: + +a) By event name, such as the latency events "xxx_latency, xxx_cnt" or + bandwidth events "xxx_flux, xxx_time". +b) By event type, such as "event=0xXXXX, event=0x1XXXX". + +Example usage of perf group:: + + $# perf stat -e "{hisi_pcie0_core0/rx_mwr_latency,port=0xffff/,hisi_pcie0_core0/rx_mwr_cnt,port=0xffff/}" + +The current driver does not support sampling. So "perf record" is unsupported. +Also attach to a task is unsupported for PCIe PMU. + +Filter options +-------------- + +1. Target filter + + PMU could only monitor the performance of traffic downstream target Root + Ports or downstream target Endpoint. PCIe PMU driver support "port" and + "bdf" interfaces for users. + Please notice that, one of these two interfaces must be set, and these two + interfaces aren't supported at the same time. If they are both set, only + "port" filter is valid. + If "port" filter not being set or is set explicitly to zero (default), the + "bdf" filter will be in effect, because "bdf=0" meaning 0000:000:00.0. + + - port + + "port" filter can be used in all PCIe PMU events, target Root Port can be + selected by configuring the 16-bits-bitmap "port". Multi ports can be + selected for AP-layer-events, and only one port can be selected for + TL/DL-layer-events. + + For example, if target Root Port is 0000:00:00.0 (x8 lanes), bit0 of + bitmap should be set, port=0x1; if target Root Port is 0000:00:04.0 (x4 + lanes), bit8 is set, port=0x100; if these two Root Ports are both + monitored, port=0x101. + + Example usage of perf:: + + $# perf stat -e hisi_pcie0_core0/rx_mwr_latency,port=0x1/ sleep 5 + + - bdf + + "bdf" filter can only be used in bandwidth events, target Endpoint is + selected by configuring BDF to "bdf". Counter only counts the bandwidth of + message requested by target Endpoint. + + For example, "bdf=0x3900" means BDF of target Endpoint is 0000:39:00.0. + + Example usage of perf:: + + $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,bdf=0x3900/ sleep 5 + +2. Trigger filter + + Event statistics start when the first time TLP length is greater/smaller + than trigger condition. You can set the trigger condition by writing + "trig_len", and set the trigger mode by writing "trig_mode". This filter can + only be used in bandwidth events. + + For example, "trig_len=4" means trigger condition is 2^4 DW, "trig_mode=0" + means statistics start when TLP length > trigger condition, "trig_mode=1" + means start when TLP length < condition. + + Example usage of perf:: + + $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,port=0xffff,trig_len=0x4,trig_mode=1/ sleep 5 + +3. Threshold filter + + Counter counts when TLP length within the specified range. You can set the + threshold by writing "thr_len", and set the threshold mode by writing + "thr_mode". This filter can only be used in bandwidth events. + + For example, "thr_len=4" means threshold is 2^4 DW, "thr_mode=0" means + counter counts when TLP length >= threshold, and "thr_mode=1" means counts + when TLP length < threshold. + + Example usage of perf:: + + $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,port=0xffff,thr_len=0x4,thr_mode=1/ sleep 5 + +4. TLP Length filter + + When counting bandwidth, the data can be composed of certain parts of TLP + packets. You can specify it through "len_mode": + + - 2'b00: Reserved (Do not use this since the behaviour is undefined) + - 2'b01: Bandwidth of TLP payloads + - 2'b10: Bandwidth of TLP headers + - 2'b11: Bandwidth of both TLP payloads and headers + + For example, "len_mode=2" means only counting the bandwidth of TLP headers + and "len_mode=3" means the final bandwidth data is composed of both TLP + headers and payloads. Default value if not specified is 2'b11. + + Example usage of perf:: + + $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,port=0xffff,len_mode=0x1/ sleep 5 |