1 ================================================
2 HiSilicon PCIe Performance Monitoring Unit (PMU)
3 ================================================
4
5 On Hip09, HiSilicon PCIe Performance Monitoring Unit (PMU) could monitor
6 bandwidth, latency, bus utilization and buffer occupancy data of PCIe.
7
8 Each PCIe Core has a PMU to monitor multi Root Ports of this PCIe Core and
9 all Endpoints downstream these Root Ports.
10
11
12 HiSilicon PCIe PMU driver
13 =========================
14
15 The PCIe PMU driver registers a perf PMU with the name of its sicl-id and PCIe
16 Core id.::
17
18 /sys/bus/event_source/hisi_pcie<sicl>_core<core>
19
20 PMU driver provides description of available events and filter options in sysfs,
21 see /sys/bus/event_source/devices/hisi_pcie<sicl>_core<core>.
22
23 The "format" directory describes all formats of the config (events) and config1
24 (filter options) fields of the perf_event_attr structure. The "events" directory
25 describes all documented events shown in perf list.
26
27 The "identifier" sysfs file allows users to identify the version of the
28 PMU hardware device.
29
30 The "bus" sysfs file allows users to get the bus number of Root Ports
31 monitored by PMU.
32
33 Example usage of perf::
34
35 $# perf list
36 hisi_pcie0_core0/rx_mwr_latency/ [kernel PMU event]
37 hisi_pcie0_core0/rx_mwr_cnt/ [kernel PMU event]
38 ------------------------------------------
39
40 $# perf stat -e hisi_pcie0_core0/rx_mwr_latency,port=0xffff/
41 $# perf stat -e hisi_pcie0_core0/rx_mwr_cnt,port=0xffff/
42
43 The related events usually used to calculate the bandwidth, latency or others.
44 They need to start and end counting at the same time, therefore related events
45 are best used in the same event group to get the expected value. There are two
46 ways to know if they are related events:
47
48 a) By event name, such as the latency events "xxx_latency, xxx_cnt" or
49 bandwidth events "xxx_flux, xxx_time".
50 b) By event type, such as "event=0xXXXX, event=0x1XXXX".
51
52 Example usage of perf group::
53
54 $# perf stat -e "{hisi_pcie0_core0/rx_mwr_latency,port=0xffff/,hisi_pcie0_core0/rx_mwr_cnt,port=0xffff/}"
55
56 The current driver does not support sampling. So "perf record" is unsupported.
57 Also attach to a task is unsupported for PCIe PMU.
58
59 Filter options
60 --------------
61
62 1. Target filter
63
64 PMU could only monitor the performance of traffic downstream target Root
65 Ports or downstream target Endpoint. PCIe PMU driver support "port" and
66 "bdf" interfaces for users.
67 Please notice that, one of these two interfaces must be set, and these two
68 interfaces aren't supported at the same time. If they are both set, only
69 "port" filter is valid.
70 If "port" filter not being set or is set explicitly to zero (default), the
71 "bdf" filter will be in effect, because "bdf=0" meaning 0000:000:00.0.
72
73 - port
74
75 "port" filter can be used in all PCIe PMU events, target Root Port can be
76 selected by configuring the 16-bits-bitmap "port". Multi ports can be
77 selected for AP-layer-events, and only one port can be selected for
78 TL/DL-layer-events.
79
80 For example, if target Root Port is 0000:00:00.0 (x8 lanes), bit0 of
81 bitmap should be set, port=0x1; if target Root Port is 0000:00:04.0 (x4
82 lanes), bit8 is set, port=0x100; if these two Root Ports are both
83 monitored, port=0x101.
84
85 Example usage of perf::
86
87 $# perf stat -e hisi_pcie0_core0/rx_mwr_latency,port=0x1/ sleep 5
88
89 - bdf
90
91 "bdf" filter can only be used in bandwidth events, target Endpoint is
92 selected by configuring BDF to "bdf". Counter only counts the bandwidth of
93 message requested by target Endpoint.
94
95 For example, "bdf=0x3900" means BDF of target Endpoint is 0000:39:00.0.
96
97 Example usage of perf::
98
99 $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,bdf=0x3900/ sleep 5
100
101 2. Trigger filter
102
103 Event statistics start when the first time TLP length is greater/smaller
104 than trigger condition. You can set the trigger condition by writing
105 "trig_len", and set the trigger mode by writing "trig_mode". This filter can
106 only be used in bandwidth events.
107
108 For example, "trig_len=4" means trigger condition is 2^4 DW, "trig_mode=0"
109 means statistics start when TLP length > trigger condition, "trig_mode=1"
110 means start when TLP length < condition.
111
112 Example usage of perf::
113
114 $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,port=0xffff,trig_len=0x4,trig_mode=1/ sleep 5
115
116 3. Threshold filter
117
118 Counter counts when TLP length within the specified range. You can set the
119 threshold by writing "thr_len", and set the threshold mode by writing
120 "thr_mode". This filter can only be used in bandwidth events.
121
122 For example, "thr_len=4" means threshold is 2^4 DW, "thr_mode=0" means
123 counter counts when TLP length >= threshold, and "thr_mode=1" means counts
124 when TLP length < threshold.
125
126 Example usage of perf::
127
128 $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,port=0xffff,thr_len=0x4,thr_mode=1/ sleep 5
129
130 4. TLP Length filter
131
132 When counting bandwidth, the data can be composed of certain parts of TLP
133 packets. You can specify it through "len_mode":
134
135 - 2'b00: Reserved (Do not use this since the behaviour is undefined)
136 - 2'b01: Bandwidth of TLP payloads
137 - 2'b10: Bandwidth of TLP headers
138 - 2'b11: Bandwidth of both TLP payloads and headers
139
140 For example, "len_mode=2" means only counting the bandwidth of TLP headers
141 and "len_mode=3" means the final bandwidth data is composed of both TLP
142 headers and payloads. Default value if not specified is 2'b11.
143
144 Example usage of perf::
145
146 $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,port=0xffff,len_mode=0x1/ sleep 5
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