Re: [PATCH v8] arm64: dts: qcom: kodiak: Add EL2 overlay

From: Mukesh Ojha

Date: Thu Jun 25 2026 - 02:34:24 EST

On Thu, Jun 25, 2026 at 09:14:41AM +0800, Miaoqing Pan wrote:
>
>
> On 6/24/2026 2:39 PM, Mukesh Ojha wrote:
> > All the existing variants Kodiak boards are using Gunyah hypervisor
> > which means that, so far, Linux-based OS could only boot in EL1 on those
> > devices. However, it is possible for us to boot Linux at EL2 on these
> > devices [1].
> >
> > When running under Gunyah, the remote processor firmware IOMMU
> > streams are controlled by Gunyah. However, without Gunyah, the IOMMU is
> > managed by the consumer of this DeviceTree. Therefore, describe the
> > firmware streams for each remote processor.
> >
> > Add a EL2-specific DT overlay and apply it to Kodiak IOT variant
> > devices to create -el2.dtb for each of them alongside "normal" dtb.
> >
> > Note that modem and media subsystems haven't been supported yet due
> > to missing dependencies. For GPU to work, zap shader is disabled and
> > in EL2 mode the kernel owns hardware watchdog which is enabled here.
> > And for wifi to work wpss copy engine memory need to be mapped for
> > WPSS firmware to work which is aligning with sc7280 chrome.
> >
> > [1]
> > https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi
> >
> > Co-developed-by: Sumit Garg <sumit.garg@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Mukesh Ojha <mukesh.ojha@xxxxxxxxxxxxxxxx>
> > ---
> > Changes in v8: https://lore.kernel.org/lkml/20260522115936.201208-2-sumit.garg@xxxxxxxxxx/
> > - Added a wpss copy engine memory similar to chrome for Wifi to work.
> > - WPSS does not have firmware Stream, so that was removed.
> > - Added wifi streams similar to chrome for wifi to work.
> > - Removed this patch from Generic Pas patch series, can be followed
> > separately.
> > - Moved Sumit as co-author as part of modification done to the patch
> > in the past.
> > - Added some more kodiak's board variants in the makefile.
> >
> > Changes in v1-v7:
> > - mpss was disabled and will be enabled once the dependencies patches
> > get merged.
> >
> > arch/arm64/boot/dts/qcom/Makefile | 12 ++++++
> > arch/arm64/boot/dts/qcom/kodiak-el2.dtso | 52 ++++++++++++++++++++++++
> > arch/arm64/boot/dts/qcom/kodiak.dtsi | 2 +-
> > 3 files changed, 65 insertions(+), 1 deletion(-)
> > create mode 100644 arch/arm64/boot/dts/qcom/kodiak-el2.dtso
> >
> > diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
> > index 6f33c4e2f09c..d2cee1190954 100644
> > --- a/arch/arm64/boot/dts/qcom/Makefile
> > +++ b/arch/arm64/boot/dts/qcom/Makefile
> > @@ -164,7 +164,11 @@ purwa-iot-evk-el2-dtbs := purwa-iot-evk.dtb x1-el2.dtbo
> > dtb-$(CONFIG_ARCH_QCOM) += purwa-iot-evk-el2.dtb
> > dtb-$(CONFIG_ARCH_QCOM) += qcm6490-fairphone-fp5.dtb
> > +
> > dtb-$(CONFIG_ARCH_QCOM) += qcm6490-idp.dtb
> > +qcm6490-idp-el2-dtbs := qcm6490-idp.dtb kodiak-el2.dtbo
> > +dtb-$(CONFIG_ARCH_QCOM) += qcm6490-idp-el2.dtb
> > +
> > dtb-$(CONFIG_ARCH_QCOM) += qcm6490-particle-tachyon.dtb
> > dtb-$(CONFIG_ARCH_QCOM) += qcm6490-shift-otter.dtb
> > dtb-$(CONFIG_ARCH_QCOM) += qcs404-evb-1000.dtb
> > @@ -176,12 +180,20 @@ qcs615-ride-el2-dtbs := qcs615-ride.dtb talos-el2.dtbo
> > dtb-$(CONFIG_ARCH_QCOM) += qcs615-ride-el2.dtb
> > dtb-$(CONFIG_ARCH_QCOM) += qcs6490-radxa-dragon-q6a.dtb
> > dtb-$(CONFIG_ARCH_QCOM) += qcs6490-rb3gen2.dtb
> > +qcs6490-rb3gen2-el2-dtbs := qcs6490-rb3gen2.dtb kodiak-el2.dtbo
> > +dtb-$(CONFIG_ARCH_QCOM) += qcs6490-rb3gen2-el2.dtb
> > qcs6490-rb3gen2-vision-mezzanine-dtbs := qcs6490-rb3gen2.dtb qcs6490-rb3gen2-vision-mezzanine.dtbo
> > qcs6490-rb3gen2-industrial-mezzanine-dtbs := qcs6490-rb3gen2.dtb qcs6490-rb3gen2-industrial-mezzanine.dtbo
> > dtb-$(CONFIG_ARCH_QCOM) += qcs6490-rb3gen2-industrial-mezzanine.dtb
> > +qcs6490-rb3gen2-industrial-mezzanine-el2-dtbs := qcs6490-rb3gen2-industrial-mezzanine.dtb kodiak-el2.dtbo
> > +dtb-$(CONFIG_ARCH_QCOM) += qcs6490-rb3gen2-industrial-mezzanine-el2.dtb
> > +
> > dtb-$(CONFIG_ARCH_QCOM) += qcs6490-rb3gen2-vision-mezzanine.dtb
> > +qcs6490-rb3gen2-vision-mezzanine-el2-dtbs := qcs6490-rb3gen2-vision-mezzanine.dtb kodiak-el2.dtbo
> > +dtb-$(CONFIG_ARCH_QCOM) += qcs6490-rb3gen2-vision-mezzanine-el2.dtb
> > +
> > dtb-$(CONFIG_ARCH_QCOM) += qcs6490-thundercomm-minipc-g1iot.dtb
> > dtb-$(CONFIG_ARCH_QCOM) += qcs6490-thundercomm-rubikpi3.dtb
> > dtb-$(CONFIG_ARCH_QCOM) += qcs8300-ride.dtb
> > diff --git a/arch/arm64/boot/dts/qcom/kodiak-el2.dtso b/arch/arm64/boot/dts/qcom/kodiak-el2.dtso
> > new file mode 100644
> > index 000000000000..91e4cda45b49
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/qcom/kodiak-el2.dtso
> > @@ -0,0 +1,52 @@
> > +// SPDX-License-Identifier: BSD-3-Clause
> > +/*
> > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> > + *
> > + * Kodiak specific modifications required to boot in EL2.
> > + */
> > +
> > +/dts-v1/;
> > +/plugin/;
> > +
> > +&gpu_zap_shader {
> > + status = "disabled";
> > +};
> > +
> > +&remoteproc_adsp {
> > + iommus = <&apps_smmu 0x1800 0x0>;
> > +};
> > +
> > +&remoteproc_cdsp {
> > + iommus = <&apps_smmu 0x11a0 0x0400>;
> > +};
> > +
> > +&remoteproc_mpss {
> > + status = "disabled";
> > +};
> > +
> > +&reserved_memory {
> > + #address-cells = <2>;
> > + #size-cells = <2>;
> > +
> > + wlan_ce_mem: wlan-ce@4cd000 {
> > + no-map;
> > + reg = <0x0 0x004cd000 0x0 0x1000>;
> > + };
> > +};
> > +
> Is it necessary to redefine |wlan_ce_mem|? Can we consider updating
> |qcs6490-rb3gen2.dts|?
> I have verified that with the following changes, *NON-KVM works fine*, and
> |wlan_ce_mem| is only used by the WCN6750 firmware.

Thanks for the review.

I was unsure about it, hence kept it as how Chrome kept it; I am
fine to keep as suggested as it seems to me these regions were
only needed for wifi-firmware mentioned, and we should not have deleted
it for qcs6490-rb3gen2.dts and idp too, will do the change that
will make this much cleaner.

>
> --- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> +++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
> @@ -26,7 +26,6 @@
> /delete-node/ &adsp_mem;
> /delete-node/ &cdsp_mem;
> /delete-node/ &video_mem;
> -/delete-node/ &wlan_ce_mem;
> /delete-node/ &wpss_mem;
> /delete-node/ &xbl_mem;
>
> @@ -1686,7 +1685,6 @@ &venus {
> };
>
> &wifi {
> - memory-region = <&wlan_fw_mem>;
> qcom,calibration-variant = "Qualcomm_rb3gen2";
>
>
> > +&venus {
> > + status = "disabled";
> > +};
> > +
> > +&watchdog {
> > + status = "okay";
> > +};
> > +
> > +&wifi {
> > + memory-region = <&wlan_fw_mem>, <&wlan_ce_mem>;
> > + status = "okay";
> > +
> > + wifi-firmware {
> > + iommus = <&apps_smmu 0x1c02 0x1>;
> > + };
> > +};
> > diff --git a/arch/arm64/boot/dts/qcom/kodiak.dtsi b/arch/arm64/boot/dts/qcom/kodiak.dtsi
> > index fa540d8c2615..2486d15fa2ba 100644
> > --- a/arch/arm64/boot/dts/qcom/kodiak.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/kodiak.dtsi
> > @@ -91,7 +91,7 @@ sleep_clk: sleep-clk {
> > };
> > };
> > - reserved-memory {
> > + reserved_memory: reserved-memory {
> > #address-cells = <2>;
> > #size-cells = <2>;
> > ranges;
>

--
-Mukesh Ojha