1. Patchew
  2. linux
  3. [PATCH v4 00/12] Peripheral Image Loader support for Qualcomm SoCs running Linux host at EL2
  4. View patch

[PATCH v4 12/12] arm64: dts: qcom: Add EL2 overlay for Lemans

Mukesh Ojha posted 12 patches 4 months ago
There is a newer version of this series
[PATCH v4 12/12] arm64: dts: qcom: Add EL2 overlay for Lemans
Posted by Mukesh Ojha 4 months ago 
All the Lemans IOT variants 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, remote processor firmware IOMMU streams is
controlled by the Gunyah however when Linux take ownership of it in EL2,
It need to configure it properly to use remote processor.

Add a EL2-specific DT overlay and apply it to Lemans IOT variant
devices to create -el2.dtb for each of them alongside "normal" dtb.

[1]
https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi

Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/Makefile        |  7 +++++-
 arch/arm64/boot/dts/qcom/lemans-el2.dtso | 41 ++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
index 296688f7cb26..e2eb6c4f8e25 100644
--- a/arch/arm64/boot/dts/qcom/Makefile
+++ b/arch/arm64/boot/dts/qcom/Makefile
@@ -35,6 +35,8 @@ dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk.dtb
 lemans-evk-camera-csi1-imx577-dtbs	:= lemans-evk.dtb lemans-evk-camera-csi1-imx577.dtbo
 
 dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk-camera-csi1-imx577.dtb
+lemans-evk-el2-dtbs := lemans-evk.dtb lemans-el2.dtbo
+dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk-el2.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= monaco-evk.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= msm8216-samsung-fortuna3g.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-acer-a1-724.dtb
@@ -136,7 +138,10 @@ dtb-$(CONFIG_ARCH_QCOM)	+= qcs6490-rb3gen2-vision-mezzanine.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qcs8300-ride.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qcs8550-aim300-aiot.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride.dtb
-dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride-r3.dtb
+qcs9100-ride-el2-dtbs := qcs9100-ride.dtb lemans-el2.dtbo
+dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride.dtb qcs9100-ride-el2.dtb
+qcs9100-ride-r3-el2-dtbs := qcs9100-ride-r3.dtb lemans-el2.dtbo
+dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride-r3.dtb qcs9100-ride-r3-el2.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qdu1000-idp.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qrb2210-rb1.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= qrb4210-rb2.dtb
diff --git a/arch/arm64/boot/dts/qcom/lemans-el2.dtso b/arch/arm64/boot/dts/qcom/lemans-el2.dtso
new file mode 100644
index 000000000000..582b0a3a291a
--- /dev/null
+++ b/arch/arm64/boot/dts/qcom/lemans-el2.dtso
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+/*
+ * Lemans specific modifications required to boot in EL2.
+ */
+
+/dts-v1/;
+/plugin/;
+
+&iris {
+	/* TODO: Add video-firmware iommus to start IRIS from EL2 */
+	status = "disabled";
+};
+
+/*
+ * When running under Gunyah, remote processor firmware IOMMU streams is
+ * controlled by the Gunyah however when we take ownership of it in EL2,
+ * we need to configure it properly to use remote processor.
+ */
+&remoteproc_adsp {
+	iommus = <&apps_smmu 0x3000 0x0>;
+};
+
+&remoteproc_cdsp0 {
+	iommus = <&apps_smmu 0x21c0 0x0400>;
+};
+
+&remoteproc_cdsp1 {
+	iommus = <&apps_smmu 0x29c0 0x0400>;
+};
+
+&remoteproc_gpdsp0 {
+       iommus = <&apps_smmu 0x38a0 0x0>;
+};
+
+&remoteproc_gpdsp1 {
+       iommus = <&apps_smmu 0x38c0 0x0>;
+};

-- 
2.50.1
Re: [PATCH v4 12/12] arm64: dts: qcom: Add EL2 overlay for Lemans
Posted by Mukesh Ojha 4 months ago 
On Tue, Oct 07, 2025 at 10:18:57PM +0530, Mukesh Ojha wrote:
> All the Lemans IOT variants 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, remote processor firmware IOMMU streams is
> controlled by the Gunyah however when Linux take ownership of it in EL2,
> It need to configure it properly to use remote processor.
> 
> Add a EL2-specific DT overlay and apply it to Lemans IOT variant
> devices to create -el2.dtb for each of them alongside "normal" dtb.
> 
> [1]
> https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi
> 
> Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
> ---
>  arch/arm64/boot/dts/qcom/Makefile        |  7 +++++-
>  arch/arm64/boot/dts/qcom/lemans-el2.dtso | 41 ++++++++++++++++++++++++++++++++
>  2 files changed, 47 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
> index 296688f7cb26..e2eb6c4f8e25 100644
> --- a/arch/arm64/boot/dts/qcom/Makefile
> +++ b/arch/arm64/boot/dts/qcom/Makefile
> @@ -35,6 +35,8 @@ dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk.dtb
>  lemans-evk-camera-csi1-imx577-dtbs	:= lemans-evk.dtb lemans-evk-camera-csi1-imx577.dtbo
>  
>  dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk-camera-csi1-imx577.dtb
> +lemans-evk-el2-dtbs := lemans-evk.dtb lemans-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk-el2.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= monaco-evk.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= msm8216-samsung-fortuna3g.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-acer-a1-724.dtb
> @@ -136,7 +138,10 @@ dtb-$(CONFIG_ARCH_QCOM)	+= qcs6490-rb3gen2-vision-mezzanine.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qcs8300-ride.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qcs8550-aim300-aiot.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride.dtb

Either this can be removed., or removed from below line.

> -dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride-r3.dtb
> +qcs9100-ride-el2-dtbs := qcs9100-ride.dtb lemans-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride.dtb qcs9100-ride-el2.dtb
> +qcs9100-ride-r3-el2-dtbs := qcs9100-ride-r3.dtb lemans-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride-r3.dtb qcs9100-ride-r3-el2.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qdu1000-idp.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qrb2210-rb1.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qrb4210-rb2.dtb
> diff --git a/arch/arm64/boot/dts/qcom/lemans-el2.dtso b/arch/arm64/boot/dts/qcom/lemans-el2.dtso
> new file mode 100644
> index 000000000000..582b0a3a291a
> --- /dev/null
> +++ b/arch/arm64/boot/dts/qcom/lemans-el2.dtso
> @@ -0,0 +1,41 @@
> +// SPDX-License-Identifier: BSD-3-Clause
> +/*
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + */
> +
> +/*
> + * Lemans specific modifications required to boot in EL2.
> + */
> +
> +/dts-v1/;
> +/plugin/;
> +
> +&iris {
> +	/* TODO: Add video-firmware iommus to start IRIS from EL2 */
> +	status = "disabled";
> +};
> +
> +/*
> + * When running under Gunyah, remote processor firmware IOMMU streams is
> + * controlled by the Gunyah however when we take ownership of it in EL2,
> + * we need to configure it properly to use remote processor.
> + */
> +&remoteproc_adsp {
> +	iommus = <&apps_smmu 0x3000 0x0>;
> +};
> +
> +&remoteproc_cdsp0 {
> +	iommus = <&apps_smmu 0x21c0 0x0400>;
> +};
> +
> +&remoteproc_cdsp1 {
> +	iommus = <&apps_smmu 0x29c0 0x0400>;
> +};
> +
> +&remoteproc_gpdsp0 {
> +       iommus = <&apps_smmu 0x38a0 0x0>;
> +};
> +
> +&remoteproc_gpdsp1 {
> +       iommus = <&apps_smmu 0x38c0 0x0>;
> +};
> 
> -- 
> 2.50.1
> 

-- 
-Mukesh Ojha
Re: [PATCH v4 12/12] arm64: dts: qcom: Add EL2 overlay for Lemans
Posted by Manivannan Sadhasivam 4 months ago 
On Tue, Oct 07, 2025 at 10:18:57PM +0530, Mukesh Ojha wrote:
> All the Lemans IOT variants 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, remote processor firmware IOMMU streams is
> controlled by the Gunyah however when Linux take ownership of it in EL2,
> It need to configure it properly to use remote processor.
> 
> Add a EL2-specific DT overlay and apply it to Lemans IOT variant
> devices to create -el2.dtb for each of them alongside "normal" dtb.
> 
> [1]
> https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi
> 
> Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
> ---
>  arch/arm64/boot/dts/qcom/Makefile        |  7 +++++-
>  arch/arm64/boot/dts/qcom/lemans-el2.dtso | 41 ++++++++++++++++++++++++++++++++
>  2 files changed, 47 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
> index 296688f7cb26..e2eb6c4f8e25 100644
> --- a/arch/arm64/boot/dts/qcom/Makefile
> +++ b/arch/arm64/boot/dts/qcom/Makefile
> @@ -35,6 +35,8 @@ dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk.dtb
>  lemans-evk-camera-csi1-imx577-dtbs	:= lemans-evk.dtb lemans-evk-camera-csi1-imx577.dtbo
>  
>  dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk-camera-csi1-imx577.dtb
> +lemans-evk-el2-dtbs := lemans-evk.dtb lemans-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk-el2.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= monaco-evk.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= msm8216-samsung-fortuna3g.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-acer-a1-724.dtb
> @@ -136,7 +138,10 @@ dtb-$(CONFIG_ARCH_QCOM)	+= qcs6490-rb3gen2-vision-mezzanine.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qcs8300-ride.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qcs8550-aim300-aiot.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride.dtb
> -dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride-r3.dtb
> +qcs9100-ride-el2-dtbs := qcs9100-ride.dtb lemans-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride.dtb qcs9100-ride-el2.dtb
> +qcs9100-ride-r3-el2-dtbs := qcs9100-ride-r3.dtb lemans-el2.dtbo
> +dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride-r3.dtb qcs9100-ride-r3-el2.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qdu1000-idp.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qrb2210-rb1.dtb
>  dtb-$(CONFIG_ARCH_QCOM)	+= qrb4210-rb2.dtb
> diff --git a/arch/arm64/boot/dts/qcom/lemans-el2.dtso b/arch/arm64/boot/dts/qcom/lemans-el2.dtso
> new file mode 100644
> index 000000000000..582b0a3a291a
> --- /dev/null
> +++ b/arch/arm64/boot/dts/qcom/lemans-el2.dtso
> @@ -0,0 +1,41 @@
> +// SPDX-License-Identifier: BSD-3-Clause
> +/*
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + */
> +
> +/*
> + * Lemans specific modifications required to boot in EL2.
> + */
> +
> +/dts-v1/;
> +/plugin/;
> +
> +&iris {
> +	/* TODO: Add video-firmware iommus to start IRIS from EL2 */

So the missing 'iommus' property is the only blocker to enable IRIS?

- Mani

> +	status = "disabled";
> +};
> +
> +/*
> + * When running under Gunyah, remote processor firmware IOMMU streams is
> + * controlled by the Gunyah however when we take ownership of it in EL2,
> + * we need to configure it properly to use remote processor.
> + */
> +&remoteproc_adsp {
> +	iommus = <&apps_smmu 0x3000 0x0>;
> +};
> +
> +&remoteproc_cdsp0 {
> +	iommus = <&apps_smmu 0x21c0 0x0400>;
> +};
> +
> +&remoteproc_cdsp1 {
> +	iommus = <&apps_smmu 0x29c0 0x0400>;
> +};
> +
> +&remoteproc_gpdsp0 {
> +       iommus = <&apps_smmu 0x38a0 0x0>;
> +};
> +
> +&remoteproc_gpdsp1 {
> +       iommus = <&apps_smmu 0x38c0 0x0>;
> +};
> 
> -- 
> 2.50.1
> 

-- 
மணிவண்ணன் சதாசிவம்
Re: [PATCH v4 12/12] arm64: dts: qcom: Add EL2 overlay for Lemans
Posted by Mukesh Ojha 4 months ago 
On Tue, Oct 07, 2025 at 02:55:04PM -0700, Manivannan Sadhasivam wrote:
> On Tue, Oct 07, 2025 at 10:18:57PM +0530, Mukesh Ojha wrote:
> > All the Lemans IOT variants 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, remote processor firmware IOMMU streams is
> > controlled by the Gunyah however when Linux take ownership of it in EL2,
> > It need to configure it properly to use remote processor.
> > 
> > Add a EL2-specific DT overlay and apply it to Lemans IOT variant
> > devices to create -el2.dtb for each of them alongside "normal" dtb.
> > 
> > [1]
> > https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi
> > 
> > Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
> > ---
> >  arch/arm64/boot/dts/qcom/Makefile        |  7 +++++-
> >  arch/arm64/boot/dts/qcom/lemans-el2.dtso | 41 ++++++++++++++++++++++++++++++++
> >  2 files changed, 47 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
> > index 296688f7cb26..e2eb6c4f8e25 100644
> > --- a/arch/arm64/boot/dts/qcom/Makefile
> > +++ b/arch/arm64/boot/dts/qcom/Makefile
> > @@ -35,6 +35,8 @@ dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk.dtb
> >  lemans-evk-camera-csi1-imx577-dtbs	:= lemans-evk.dtb lemans-evk-camera-csi1-imx577.dtbo
> >  
> >  dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk-camera-csi1-imx577.dtb
> > +lemans-evk-el2-dtbs := lemans-evk.dtb lemans-el2.dtbo
> > +dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk-el2.dtb
> >  dtb-$(CONFIG_ARCH_QCOM)	+= monaco-evk.dtb
> >  dtb-$(CONFIG_ARCH_QCOM)	+= msm8216-samsung-fortuna3g.dtb
> >  dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-acer-a1-724.dtb
> > @@ -136,7 +138,10 @@ dtb-$(CONFIG_ARCH_QCOM)	+= qcs6490-rb3gen2-vision-mezzanine.dtb
> >  dtb-$(CONFIG_ARCH_QCOM)	+= qcs8300-ride.dtb
> >  dtb-$(CONFIG_ARCH_QCOM)	+= qcs8550-aim300-aiot.dtb
> >  dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride.dtb
> > -dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride-r3.dtb
> > +qcs9100-ride-el2-dtbs := qcs9100-ride.dtb lemans-el2.dtbo
> > +dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride.dtb qcs9100-ride-el2.dtb
> > +qcs9100-ride-r3-el2-dtbs := qcs9100-ride-r3.dtb lemans-el2.dtbo
> > +dtb-$(CONFIG_ARCH_QCOM)	+= qcs9100-ride-r3.dtb qcs9100-ride-r3-el2.dtb
> >  dtb-$(CONFIG_ARCH_QCOM)	+= qdu1000-idp.dtb
> >  dtb-$(CONFIG_ARCH_QCOM)	+= qrb2210-rb1.dtb
> >  dtb-$(CONFIG_ARCH_QCOM)	+= qrb4210-rb2.dtb
> > diff --git a/arch/arm64/boot/dts/qcom/lemans-el2.dtso b/arch/arm64/boot/dts/qcom/lemans-el2.dtso
> > new file mode 100644
> > index 000000000000..582b0a3a291a
> > --- /dev/null
> > +++ b/arch/arm64/boot/dts/qcom/lemans-el2.dtso
> > @@ -0,0 +1,41 @@
> > +// SPDX-License-Identifier: BSD-3-Clause
> > +/*
> > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> > + */
> > +
> > +/*
> > + * Lemans specific modifications required to boot in EL2.
> > + */
> > +
> > +/dts-v1/;
> > +/plugin/;
> > +
> > +&iris {
> > +	/* TODO: Add video-firmware iommus to start IRIS from EL2 */
> 
> So the missing 'iommus' property is the only blocker to enable IRIS?

Yes, but this would require some changes in the driver as well to create
a platform device for the firmware and IOMMU domain, and to attach the
firmware device to the domain.

There was some discussion around this in v2[1], where I added support
for video. However, the change involved hooking into the video-firmware
property, which was used for Venus.  There were concerns[2] about following
the same approach for Iris, and due to that, we have dropped video
support for now.  However, an RFC has been posted from our side to
handle such scenarios[3], as of now unclear about the direction for
Iris.


[1] https://lore.kernel.org/lkml/aKooCFoV3ZYwOMRx@linaro.org/

[2] https://lore.kernel.org/lkml/20250627-video_cb-v3-0-51e18c0ffbce@quicinc.com/

[3] https://lore.kernel.org/all/20250928171718.436440-1-charan.kalla@oss.qualcomm.com/

[4] https://lore.kernel.org/lkml/4a32bbec-2baf-4210-a7c1-1ddcd45d30c8@oss.qualcomm.com/
> 
> - Mani
> 
> > +	status = "disabled";
> > +};
> > +
> > +/*
> > + * When running under Gunyah, remote processor firmware IOMMU streams is
> > + * controlled by the Gunyah however when we take ownership of it in EL2,
> > + * we need to configure it properly to use remote processor.
> > + */
> > +&remoteproc_adsp {
> > +	iommus = <&apps_smmu 0x3000 0x0>;
> > +};
> > +
> > +&remoteproc_cdsp0 {
> > +	iommus = <&apps_smmu 0x21c0 0x0400>;
> > +};
> > +
> > +&remoteproc_cdsp1 {
> > +	iommus = <&apps_smmu 0x29c0 0x0400>;
> > +};
> > +
> > +&remoteproc_gpdsp0 {
> > +       iommus = <&apps_smmu 0x38a0 0x0>;
> > +};
> > +
> > +&remoteproc_gpdsp1 {
> > +       iommus = <&apps_smmu 0x38c0 0x0>;
> > +};
> > 
> > -- 
> > 2.50.1
> > 
> 
> -- 
> மணிவண்ணன் சதாசிவம்

-- 
-Mukesh Ojha
Re: [PATCH v4 12/12] arm64: dts: qcom: Add EL2 overlay for Lemans
Posted by Konrad Dybcio 4 months ago 
On 10/8/25 9:32 AM, Mukesh Ojha wrote:
> On Tue, Oct 07, 2025 at 02:55:04PM -0700, Manivannan Sadhasivam wrote:
>> On Tue, Oct 07, 2025 at 10:18:57PM +0530, Mukesh Ojha wrote:
>>> All the Lemans IOT variants 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, remote processor firmware IOMMU streams is
>>> controlled by the Gunyah however when Linux take ownership of it in EL2,
>>> It need to configure it properly to use remote processor.
>>>
>>> Add a EL2-specific DT overlay and apply it to Lemans IOT variant
>>> devices to create -el2.dtb for each of them alongside "normal" dtb.
>>>
>>> [1]
>>> https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi
>>>
>>> Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
>>> ---

[...]

>>> +&iris {
>>> +	/* TODO: Add video-firmware iommus to start IRIS from EL2 */
>>
>> So the missing 'iommus' property is the only blocker to enable IRIS?
> 
> Yes, but this would require some changes in the driver as well to create
> a platform device for the firmware and IOMMU domain, and to attach the
> firmware device to the domain.

"yes, but actually no"

> 
> There was some discussion around this in v2[1], where I added support
> for video. However, the change involved hooking into the video-firmware
> property, which was used for Venus.  There were concerns[2] about following
> the same approach for Iris, and due to that, we have dropped video
> support for now.  However, an RFC has been posted from our side to
> handle such scenarios[3], as of now unclear about the direction for
> Iris.
> 
> 
> [1] https://lore.kernel.org/lkml/aKooCFoV3ZYwOMRx@linaro.org/
> 
> [2] https://lore.kernel.org/lkml/20250627-video_cb-v3-0-51e18c0ffbce@quicinc.com/
> 
> [3] https://lore.kernel.org/all/20250928171718.436440-1-charan.kalla@oss.qualcomm.com/
> 
> [4] https://lore.kernel.org/lkml/4a32bbec-2baf-4210-a7c1-1ddcd45d30c8@oss.qualcomm.com/

Reword the comment to "/* More driver work is needed */" since there
is nothing more you can do at the moment and you most likely don't
want to block your series on resolving the above entanglement

Konrad
Re: [PATCH v4 12/12] arm64: dts: qcom: Add EL2 overlay for Lemans
Posted by Mukesh Ojha 4 months ago 
On Wed, Oct 08, 2025 at 12:13:03PM +0200, Konrad Dybcio wrote:
> On 10/8/25 9:32 AM, Mukesh Ojha wrote:
> > On Tue, Oct 07, 2025 at 02:55:04PM -0700, Manivannan Sadhasivam wrote:
> >> On Tue, Oct 07, 2025 at 10:18:57PM +0530, Mukesh Ojha wrote:
> >>> All the Lemans IOT variants 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, remote processor firmware IOMMU streams is
> >>> controlled by the Gunyah however when Linux take ownership of it in EL2,
> >>> It need to configure it properly to use remote processor.
> >>>
> >>> Add a EL2-specific DT overlay and apply it to Lemans IOT variant
> >>> devices to create -el2.dtb for each of them alongside "normal" dtb.
> >>>
> >>> [1]
> >>> https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi
> >>>
> >>> Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
> >>> ---
> 
> [...]
> 
> >>> +&iris {
> >>> +	/* TODO: Add video-firmware iommus to start IRIS from EL2 */
> >>
> >> So the missing 'iommus' property is the only blocker to enable IRIS?
> > 
> > Yes, but this would require some changes in the driver as well to create
> > a platform device for the firmware and IOMMU domain, and to attach the
> > firmware device to the domain.
> 
> "yes, but actually no"
> 
> > 
> > There was some discussion around this in v2[1], where I added support
> > for video. However, the change involved hooking into the video-firmware
> > property, which was used for Venus.  There were concerns[2] about following
> > the same approach for Iris, and due to that, we have dropped video
> > support for now.  However, an RFC has been posted from our side to
> > handle such scenarios[3], as of now unclear about the direction for
> > Iris.
> > 
> > 
> > [1] https://lore.kernel.org/lkml/aKooCFoV3ZYwOMRx@linaro.org/
> > 
> > [2] https://lore.kernel.org/lkml/20250627-video_cb-v3-0-51e18c0ffbce@quicinc.com/
> > 
> > [3] https://lore.kernel.org/all/20250928171718.436440-1-charan.kalla@oss.qualcomm.com/
> > 
> > [4] https://lore.kernel.org/lkml/4a32bbec-2baf-4210-a7c1-1ddcd45d30c8@oss.qualcomm.com/
> 
> Reword the comment to "/* More driver work is needed */" since there
> is nothing more you can do at the moment and you most likely don't
> want to block your series on resolving the above entanglement

Sure.

> 
> Konrad

-- 
-Mukesh Ojha

Patchew 2.1-devel-b67e4c2

© 2016 - 2026 Red Hat, Inc.