Most Qualcomm platforms feature Gunyah hypervisor which handles IOMMU
configuration for remote processor and when it is not present, the
operating system must perform these configurations instead and for that
firmware stream should be presented to the operating system. Hence, add
iommus property as optional property for PAS supported devices.

Acked-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml b/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml
index 63a82e7a8bf8..68c17bf18987 100644
--- a/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml
+++ b/Documentation/devicetree/bindings/remoteproc/qcom,pas-common.yaml
@@ -44,6 +44,9 @@ properties:
       - const: stop-ack
       - const: shutdown-ack
 
+  iommus:
+    maxItems: 1
+
   power-domains:
     minItems: 1
     maxItems: 3

-- 
2.50.1

On 04/11/2025 08:35, Mukesh Ojha wrote:
> Most Qualcomm platforms feature Gunyah hypervisor which handles IOMMU

I don't think that's true. Washn't Gunyah something new? Like since
SM8550? Look how many Qualcomm platforms we have in the arm/qcom.yaml
bindings - for sure most of them are not post SM8550.

> configuration for remote processor and when it is not present, the
> operating system must perform these configurations instead and for that
> firmware stream should be presented to the operating system. Hence, add
> iommus property as optional property for PAS supported devices.

So which platforms actually need to do this?

I really do not understand why you are adding this to SDX55 and several
others.



Best regards,
Krzysztof

On Wed, Nov 05, 2025 at 08:17:14AM +0100, Krzysztof Kozlowski wrote:
> On 04/11/2025 08:35, Mukesh Ojha wrote:
> > Most Qualcomm platforms feature Gunyah hypervisor which handles IOMMU
> 
> I don't think that's true. Washn't Gunyah something new? Like since
> SM8550? Look how many Qualcomm platforms we have in the arm/qcom.yaml
> bindings - for sure most of them are not post SM8550.


I should have rephrased it, thanks 

"Qualcomm platform which feature QHEE based hypervisor or a module in Gunyah
 ... "

> 
> > configuration for remote processor and when it is not present, the
> > operating system must perform these configurations instead and for that
> > firmware stream should be presented to the operating system. Hence, add
> > iommus property as optional property for PAS supported devices.
> 
> So which platforms actually need to do this?

As I said above, almost every platform which features QHEE or Gunyah
hypervisor that support PAS based remoteproc subsystem should have this.

> 
> I really do not understand why you are adding this to SDX55 and several
> others.

Firmware IOMMU context bank was always managed by QHEE hypervisor or
Gunyah it is more of never mentioned schema in PAS schema. So, even
SDX55 should have these as optional.

> 
> 
> 
> Best regards,
> Krzysztof

-- 
-Mukesh Ojha

On 11/5/25 9:34 AM, Mukesh Ojha wrote:
> On Wed, Nov 05, 2025 at 08:17:14AM +0100, Krzysztof Kozlowski wrote:
>> On 04/11/2025 08:35, Mukesh Ojha wrote:
>>> Most Qualcomm platforms feature Gunyah hypervisor which handles IOMMU
>>
>> I don't think that's true. Washn't Gunyah something new? Like since
>> SM8550? Look how many Qualcomm platforms we have in the arm/qcom.yaml
>> bindings - for sure most of them are not post SM8550.
> 
> 
> I should have rephrased it, thanks 
> 
> "Qualcomm platform which feature QHEE based hypervisor or a module in Gunyah
>  ... "
> 
>>
>>> configuration for remote processor and when it is not present, the
>>> operating system must perform these configurations instead and for that
>>> firmware stream should be presented to the operating system. Hence, add
>>> iommus property as optional property for PAS supported devices.
>>
>> So which platforms actually need to do this?
> 
> As I said above, almost every platform which features QHEE or Gunyah
> hypervisor that support PAS based remoteproc subsystem should have this.

For added context, QHEE (pre-Gunyah hyp) has been with us almost forever

Konrad