537216e59f
Add a user guide to show how to use DDR PMU to monitor DDR bandwidth on Amlogic G12 SoC Signed-off-by: Jiucheng Xu <jiucheng.xu@amlogic.com> Reviewed-by: Chris Healy <healych@amazon.com> Link: https://lore.kernel.org/r/20221121021602.3306998-2-jiucheng.xu@amlogic.com Signed-off-by: Will Deacon <will@kernel.org>
71 lines
2.4 KiB
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71 lines
2.4 KiB
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.. SPDX-License-Identifier: GPL-2.0
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===========================================================
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Amlogic SoC DDR Bandwidth Performance Monitoring Unit (PMU)
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===========================================================
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The Amlogic Meson G12 SoC contains a bandwidth monitor inside DRAM controller.
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The monitor includes 4 channels. Each channel can count the request accessing
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DRAM. The channel can count up to 3 AXI port simultaneously. It can be helpful
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to show if the performance bottleneck is on DDR bandwidth.
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Currently, this driver supports the following 5 perf events:
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+ meson_ddr_bw/total_rw_bytes/
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+ meson_ddr_bw/chan_1_rw_bytes/
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+ meson_ddr_bw/chan_2_rw_bytes/
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+ meson_ddr_bw/chan_3_rw_bytes/
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+ meson_ddr_bw/chan_4_rw_bytes/
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meson_ddr_bw/chan_{1,2,3,4}_rw_bytes/ events are channel-specific events.
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Each channel support filtering, which can let the channel to monitor
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individual IP module in SoC.
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Below are DDR access request event filter keywords:
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+ arm - from CPU
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+ vpu_read1 - from OSD + VPP read
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+ gpu - from 3D GPU
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+ pcie - from PCIe controller
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+ hdcp - from HDCP controller
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+ hevc_front - from HEVC codec front end
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+ usb3_0 - from USB3.0 controller
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+ hevc_back - from HEVC codec back end
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+ h265enc - from HEVC encoder
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+ vpu_read2 - from DI read
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+ vpu_write1 - from VDIN write
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+ vpu_write2 - from di write
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+ vdec - from legacy codec video decoder
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+ hcodec - from H264 encoder
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+ ge2d - from ge2d
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+ spicc1 - from SPI controller 1
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+ usb0 - from USB2.0 controller 0
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+ dma - from system DMA controller 1
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+ arb0 - from arb0
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+ sd_emmc_b - from SD eMMC b controller
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+ usb1 - from USB2.0 controller 1
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+ audio - from Audio module
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+ sd_emmc_c - from SD eMMC c controller
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+ spicc2 - from SPI controller 2
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+ ethernet - from Ethernet controller
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Examples:
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+ Show the total DDR bandwidth per seconds:
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.. code-block:: bash
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perf stat -a -e meson_ddr_bw/total_rw_bytes/ -I 1000 sleep 10
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+ Show individual DDR bandwidth from CPU and GPU respectively, as well as
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sum of them:
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.. code-block:: bash
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perf stat -a -e meson_ddr_bw/chan_1_rw_bytes,arm=1/ -I 1000 sleep 10
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perf stat -a -e meson_ddr_bw/chan_2_rw_bytes,gpu=1/ -I 1000 sleep 10
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perf stat -a -e meson_ddr_bw/chan_3_rw_bytes,arm=1,gpu=1/ -I 1000 sleep 10
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