On Arm systems, some platform devices behind an SMMU may support the PASID
feature, which offers multiple address space. Let the firmware tell us
when a device supports PASID.
Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Jean-Philippe Brucker <[email protected]>
---
Previous discussion on this patch last year:
https://patchwork.ozlabs.org/patch/872275/
I split PASID and stall definitions, keeping only PASID here.
---
Documentation/devicetree/bindings/iommu/iommu.txt | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/iommu/iommu.txt b/Documentation/devicetree/bindings/iommu/iommu.txt
index 5a8b4624defc..3c36334e4f94 100644
--- a/Documentation/devicetree/bindings/iommu/iommu.txt
+++ b/Documentation/devicetree/bindings/iommu/iommu.txt
@@ -86,6 +86,12 @@ have a means to turn off translation. But it is invalid in such cases to
disable the IOMMU's device tree node in the first place because it would
prevent any driver from properly setting up the translations.
+Optional properties:
+--------------------
+- pasid-num-bits: Some masters support multiple address spaces for DMA, by
+ tagging DMA transactions with an address space identifier. By default,
+ this is 0, which means that the device only has one address space.
+
Notes:
======
--
2.21.0
Hi Jean,
On 6/10/19 8:47 PM, Jean-Philippe Brucker wrote:
> On Arm systems, some platform devices behind an SMMU may support the PASID
> feature, which offers multiple address space. Let the firmware tell us
> when a device supports PASID.
>
> Reviewed-by: Rob Herring <[email protected]>
> Signed-off-by: Jean-Philippe Brucker <[email protected]>
> ---
> Previous discussion on this patch last year:
> https://patchwork.ozlabs.org/patch/872275/
> I split PASID and stall definitions, keeping only PASID here.
> ---
> Documentation/devicetree/bindings/iommu/iommu.txt | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/iommu/iommu.txt b/Documentation/devicetree/bindings/iommu/iommu.txt
> index 5a8b4624defc..3c36334e4f94 100644
> --- a/Documentation/devicetree/bindings/iommu/iommu.txt
> +++ b/Documentation/devicetree/bindings/iommu/iommu.txt
> @@ -86,6 +86,12 @@ have a means to turn off translation. But it is invalid in such cases to
> disable the IOMMU's device tree node in the first place because it would
> prevent any driver from properly setting up the translations.
>
> +Optional properties:
> +--------------------
> +- pasid-num-bits: Some masters support multiple address spaces for DMA, by
> + tagging DMA transactions with an address space identifier. By default,
> + this is 0, which means that the device only has one address space.
> +
Reviewed-by: Eric Auger <[email protected]>
Thanks
Eric
>
> Notes:
> ======
>