[PATCH v5 4/4] arm64: dts: qcom: sdm845: Add CPU BWMON

Krzysztof Kozlowski krzysztof.kozlowski at linaro.org
Wed Jun 29 00:52:50 PDT 2022


Add device node for CPU-memory BWMON device (bandwidth monitoring) on
SDM845 measuring bandwidth between CPU (gladiator_noc) and Last Level
Cache (memnoc).  Usage of this BWMON allows to remove fixed bandwidth
votes from cpufreq (CPU nodes) thus achieve high memory throughput even
with lower CPU frequencies.

Co-developed-by: Thara Gopinath <thara.gopinath at gmail.com>
Signed-off-by: Thara Gopinath <thara.gopinath at gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski at linaro.org>
---
 arch/arm64/boot/dts/qcom/sdm845.dtsi | 38 ++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
index 83e8b63f0910..e0f088996390 100644
--- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
+++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
@@ -2026,6 +2026,44 @@ llcc: system-cache-controller at 1100000 {
 			interrupts = <GIC_SPI 582 IRQ_TYPE_LEVEL_HIGH>;
 		};
 
+		pmu at 1436400 {
+			compatible = "qcom,sdm845-cpu-bwmon", "qcom,msm8998-cpu-bwmon";
+			reg = <0 0x01436400 0 0x600>;
+			interrupts = <GIC_SPI 581 IRQ_TYPE_LEVEL_HIGH>;
+			interconnects = <&gladiator_noc MASTER_APPSS_PROC 3 &mem_noc SLAVE_LLCC 3>;
+
+			operating-points-v2 = <&cpu_bwmon_opp_table>;
+
+			cpu_bwmon_opp_table: opp-table {
+				compatible = "operating-points-v2";
+
+				/*
+				 * The interconnect paths bandwidths taken from
+				 * cpu4_opp_table bandwidth.
+				 * They also match different tables from
+				 * msm-4.9 downstream kernel:
+				 *  - the OSM L3 from bandwidth table of
+				 *    qcom,cpu4-l3lat-mon (qcom,core-dev-table);
+				 *    bus width: 16 bytes;
+				 */
+				opp-0 {
+					opp-peak-kBps = <4800000>;
+				};
+				opp-1 {
+					opp-peak-kBps = <9216000>;
+				};
+				opp-2 {
+					opp-peak-kBps = <15052800>;
+				};
+				opp-3 {
+					opp-peak-kBps = <20889600>;
+				};
+				opp-4 {
+					opp-peak-kBps = <25497600>;
+				};
+			};
+		};
+
 		pcie0: pci at 1c00000 {
 			compatible = "qcom,pcie-sdm845";
 			reg = <0 0x01c00000 0 0x2000>,
-- 
2.34.1




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