Hi Krzysztof,
Thanks for working on this!
On 1.06.22 13:11, Krzysztof Kozlowski wrote:
Bandwidth monitoring (BWMON) sits between various subsytems like CPU,
GPU, Last Level caches and memory subsystem. The BWMON can be
configured to monitor the data throuhput between memory and other
subsytems. The throughput is measured within specified sampling window
and is used to vote for corresponding interconnect bandwidth.
Current implementation brings support for BWMON v4, used for example on
SDM845 to measure 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.
I am curious if you ran any tests - e.g set the CPU to some fixed
frequency and run memory throughput benchmarks with/without this
driver? Could you share any data?
Co-developed-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
---
MAINTAINERS | 7 +
drivers/soc/qcom/Kconfig | 15 ++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/icc-bwmon.c | 421 +++++++++++++++++++++++++++++++++++
4 files changed, 444 insertions(+)
create mode 100644 drivers/soc/qcom/icc-bwmon.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 6157e706ed02..bc123f706256 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16376,6 +16376,13 @@ S: Maintained
F: Documentation/devicetree/bindings/i2c/i2c-qcom-cci.txt
F: drivers/i2c/busses/i2c-qcom-cci.c
+QUALCOMM INTERCONNECT BWMON DRIVER
+M: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
+L: linux-arm-msm@xxxxxxxxxxxxxxx
+S: Maintained
+F: Documentation/devicetree/bindings/interconnect/qcom,sdm845-cpu-bwmon.yaml
+F: drivers/soc/qcom/icc-bwmon.c
+
QUALCOMM IOMMU
M: Rob Clark <robdclark@xxxxxxxxx>
L: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index e718b8735444..35c5192dcfc7 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -228,4 +228,19 @@ config QCOM_APR
application processor and QDSP6. APR is
used by audio driver to configure QDSP6
ASM, ADM and AFE modules.
+
+config QCOM_ICC_BWMON
+ tristate "QCOM Interconnect Bandwidth Monitor driver"
+ depends on ARCH_QCOM || COMPILE_TEST
+ select PM_OPP
+ help
+ Sets up driver monitoring bandwidth on various interconnects and
+ based on that voting for interconnect bandwidth, adjusting their
+ speed to current demand.
+ Current implementation brings support for BWMON v4, used for example
+ on SDM845 to measure 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.
+
endmenu
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 70d5de69fd7b..d66604aff2b0 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -28,3 +28,4 @@ obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o
obj-$(CONFIG_QCOM_RPMHPD) += rpmhpd.o
obj-$(CONFIG_QCOM_RPMPD) += rpmpd.o
obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) += kryo-l2-accessors.o
+obj-$(CONFIG_QCOM_ICC_BWMON) += icc-bwmon.o
diff --git a/drivers/soc/qcom/icc-bwmon.c b/drivers/soc/qcom/icc-bwmon.c
new file mode 100644
index 000000000000..1eed075545db
--- /dev/null
+++ b/drivers/soc/qcom/icc-bwmon.c
@@ -0,0 +1,421 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2021-2022 Linaro Ltd
+ * Author: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>, based on
+ * previous work of Thara Gopinath and msm-4.9 downstream sources.
+ */
+#include <linux/interconnect.h>
Is this used?
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/sizes.h>
Ditto.
Thanks,
Georgi
