Re: [PATCH 1/6] dt-bindings: misc: fastrpc: Add memory-region property for context bank

[Krzysztof Kozlowski <krzk@kernel.org>]

On Wed, Aug 26, 2026 at 07:15:43PM +0530, Vinayak Katoch wrote:
> Add an optional memory-region property to the context bank node schema.
> The driver uses its presence to identify a context bank as dedicated for
> extended IOVA mapping and programs the SMMU with an iommu-addresses
> range to push allocations into the wider address space.

I hope you are not solving in a third or fourth way the same problem
that Iris/Venus, QDA and one more block have.

> 
> Relax #address-cells to enum: [1, 2] and #size-cells to enum: [0, 2] to
> allow platforms that require 64-bit values in iommu-addresses to pass
> binding validation.
> 
> Signed-off-by: Vinayak Katoch <vinayak.katoch@oss.qualcomm.com>
> ---
>  Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml b/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
> index e945c8ba75e3..f9830ef37814 100644
> --- a/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
> +++ b/Documentation/devicetree/bindings/misc/qcom,fastrpc.yaml
> @@ -73,10 +73,10 @@ properties:
>      $ref: /schemas/types.yaml#/definitions/uint32-array
>  
>    "#address-cells":
> -    const: 1
> +    enum: [1, 2]
>  
>    "#size-cells":
> -    const: 0
> +    enum: [0, 2]
>  
>  patternProperties:
>    "(compute-)?cb@[0-9]*$":
> @@ -98,6 +98,14 @@ patternProperties:
>          minItems: 1
>          maxItems: 10
>  
> +      memory-region:
> +        maxItems: 1
> +        description:
> +          Phandle to a reserved-memory node whose iommu-addresses property
> +          blocks the lower IOVA range, forcing allocations into the extended
> +          address space. Its presence marks this context bank as an extended
> +          mapping bank.

So far looks the same as:
https://lore.kernel.org/all/20260807-iris_iova_600mb_fix-v1-4-3996f67e33f9@oss.qualcomm.com/

If it is not the same problem, then please explain. Otherwise wait for
resolution of Iris patchset.

Best regards,
Krzysztof