Re: [PATCH v2 2/2] dt-bindings: Document "UntrustedDevice" property for PCI devices

[Rob Herring <robh@kernel.org>]

On Tue, Feb 01, 2022 at 06:01:03PM -0800, Rajat Jain wrote:
> Add the new "UntrustedDevice" property for PCI devices. This property
> is optional and can be applied to any PCI device.
> 
> Signed-off-by: Rajat Jain <rajatja@google.com>
> ---
> v2: Initial version (added documentation based on comments)
> v1: Does not exist.
> 
>  Documentation/devicetree/bindings/pci/pci.txt | 35 +++++++++++++++++++
>  1 file changed, 35 insertions(+)

New properties have to be in a schema which resides here:

https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/pci/pci-bus.yaml

> 
> diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
> index 6a8f2874a24d..bc1ba10f51e1 100644
> --- a/Documentation/devicetree/bindings/pci/pci.txt
> +++ b/Documentation/devicetree/bindings/pci/pci.txt
> @@ -82,3 +82,38 @@ pcie@10000000 {
>  		external-facing;
>  	};
>  };
> +
> +PCI Device Properties
> +---------------------
> +Following optional properties may be present for any PCI device:
> +
> +- UntrustedDevice:
> +   When present, this property is an indicator that this PCI device (and
> +   any downstream devices) are to be treated as untrusted by the kernel.
> +   The kernel can, for example, use this information to isolate such
> +   devices using a strict DMA protection via the IOMMU.
> +
> +   Example device tree node:
> +	pcie@0008 {
> +		/* PCI device 00:01.0 is an untrusted device */
> +		reg = <0x00000800 0 0 0 0>;
> +		UntrustedDevice = <1>;
> +	};
> +
> +   Example ACPI node:

Humm, your caret case smelled like ACPI to begin with. As far as ACPI 
bindings in Documentation/devicetree/bindings/ are concerned, NAK.