1.. SPDX-License-Identifier: GPL-2.0 2 3=========================================================== 4Amlogic SoC DDR Bandwidth Performance Monitoring Unit (PMU) 5=========================================================== 6 7The Amlogic Meson G12 SoC contains a bandwidth monitor inside DRAM controller. 8The monitor includes 4 channels. Each channel can count the request accessing 9DRAM. The channel can count up to 3 AXI port simultaneously. It can be helpful 10to show if the performance bottleneck is on DDR bandwidth. 11 12Currently, this driver supports the following 5 perf events: 13 14+ meson_ddr_bw/total_rw_bytes/ 15+ meson_ddr_bw/chan_1_rw_bytes/ 16+ meson_ddr_bw/chan_2_rw_bytes/ 17+ meson_ddr_bw/chan_3_rw_bytes/ 18+ meson_ddr_bw/chan_4_rw_bytes/ 19 20meson_ddr_bw/chan_{1,2,3,4}_rw_bytes/ events are channel-specific events. 21Each channel support filtering, which can let the channel to monitor 22individual IP module in SoC. 23 24Below are DDR access request event filter keywords: 25 26+ arm - from CPU 27+ vpu_read1 - from OSD + VPP read 28+ gpu - from 3D GPU 29+ pcie - from PCIe controller 30+ hdcp - from HDCP controller 31+ hevc_front - from HEVC codec front end 32+ usb3_0 - from USB3.0 controller 33+ hevc_back - from HEVC codec back end 34+ h265enc - from HEVC encoder 35+ vpu_read2 - from DI read 36+ vpu_write1 - from VDIN write 37+ vpu_write2 - from di write 38+ vdec - from legacy codec video decoder 39+ hcodec - from H264 encoder 40+ ge2d - from ge2d 41+ spicc1 - from SPI controller 1 42+ usb0 - from USB2.0 controller 0 43+ dma - from system DMA controller 1 44+ arb0 - from arb0 45+ sd_emmc_b - from SD eMMC b controller 46+ usb1 - from USB2.0 controller 1 47+ audio - from Audio module 48+ sd_emmc_c - from SD eMMC c controller 49+ spicc2 - from SPI controller 2 50+ ethernet - from Ethernet controller 51 52 53Examples: 54 55 + Show the total DDR bandwidth per seconds: 56 57 .. code-block:: bash 58 59 perf stat -a -e meson_ddr_bw/total_rw_bytes/ -I 1000 sleep 10 60 61 62 + Show individual DDR bandwidth from CPU and GPU respectively, as well as 63 sum of them: 64 65 .. code-block:: bash 66 67 perf stat -a -e meson_ddr_bw/chan_1_rw_bytes,arm=1/ -I 1000 sleep 10 68 perf stat -a -e meson_ddr_bw/chan_2_rw_bytes,gpu=1/ -I 1000 sleep 10 69 perf stat -a -e meson_ddr_bw/chan_3_rw_bytes,arm=1,gpu=1/ -I 1000 sleep 10 70 71