On 16/09/2022 14:22, Jean-Philippe Brucker wrote:
> Convert the binding that describes the virtio-pci based IOMMU to DT
> schema. Change the compatible string to "pci<vendor>,<device>", which is
> defined by the PCI Bus Binding, but keep "virtio,pci-iommu" as an option
> for backward compatibility.
>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> ---
> .../devicetree/bindings/virtio/iommu.txt | 66 --------------
> .../devicetree/bindings/virtio/iommu.yaml | 86 +++++++++++++++++++
> 2 files changed, 86 insertions(+), 66 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/virtio/iommu.txt
> create mode 100644 Documentation/devicetree/bindings/virtio/iommu.yaml
>
> diff --git a/Documentation/devicetree/bindings/virtio/iommu.txt b/Documentation/devicetree/bindings/virtio/iommu.txt
> deleted file mode 100644
> index 2407fea0651c..000000000000
> --- a/Documentation/devicetree/bindings/virtio/iommu.txt
> +++ /dev/null
> @@ -1,66 +0,0 @@
> -* virtio IOMMU PCI device
> -
> -When virtio-iommu uses the PCI transport, its programming interface is
> -discovered dynamically by the PCI probing infrastructure. However the
> -device tree statically describes the relation between IOMMU and DMA
> -masters. Therefore, the PCI root complex that hosts the virtio-iommu
> -contains a child node representing the IOMMU device explicitly.
> -
> -Required properties:
> -
> -- compatible: Should be "virtio,pci-iommu"
> -- reg: PCI address of the IOMMU. As defined in the PCI Bus
> - Binding reference [1], the reg property is a five-cell
> - address encoded as (phys.hi phys.mid phys.lo size.hi
> - size.lo). phys.hi should contain the device's BDF as
> - 0b00000000 bbbbbbbb dddddfff 00000000. The other cells
> - should be zero.
> -- #iommu-cells: Each platform DMA master managed by the IOMMU is assigned
> - an endpoint ID, described by the "iommus" property [2].
> - For virtio-iommu, #iommu-cells must be 1.
> -
> -Notes:
> -
> -- DMA from the IOMMU device isn't managed by another IOMMU. Therefore the
> - virtio-iommu node doesn't have an "iommus" property, and is omitted from
> - the iommu-map property of the root complex.
> -
> -Example:
> -
> -pcie@10000000 {
> - compatible = "pci-host-ecam-generic";
> - ...
> -
> - /* The IOMMU programming interface uses slot 00:01.0 */
> - iommu0: iommu@0008 {
> - compatible = "virtio,pci-iommu";
> - reg = <0x00000800 0 0 0 0>;
> - #iommu-cells = <1>;
> - };
> -
> - /*
> - * The IOMMU manages all functions in this PCI domain except
> - * itself. Omit BDF 00:01.0.
> - */
> - iommu-map = <0x0 &iommu0 0x0 0x8>
> - <0x9 &iommu0 0x9 0xfff7>;
> -};
> -
> -pcie@20000000 {
> - compatible = "pci-host-ecam-generic";
> - ...
> - /*
> - * The IOMMU also manages all functions from this domain,
> - * with endpoint IDs 0x10000 - 0x1ffff
> - */
> - iommu-map = <0x0 &iommu0 0x10000 0x10000>;
> -};
> -
> -ethernet@fe001000 {
> - ...
> - /* The IOMMU manages this platform device with endpoint ID 0x20000 */
> - iommus = <&iommu0 0x20000>;
> -};
> -
> -[1] Documentation/devicetree/bindings/pci/pci.txt
> -[2] Documentation/devicetree/bindings/iommu/iommu.txt
> diff --git a/Documentation/devicetree/bindings/virtio/iommu.yaml b/Documentation/devicetree/bindings/virtio/iommu.yaml
> new file mode 100644
> index 000000000000..d5bbb8ab9603
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/virtio/iommu.yaml
> @@ -0,0 +1,86 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/virtio/iommu.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: virtio-iommu device using the virtio-pci transport
> +
> +maintainers:
> + - Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
> +
> +description: |
> + When virtio-iommu uses the PCI transport, its programming interface is
> + discovered dynamically by the PCI probing infrastructure. However the
> + device tree statically describes the relation between IOMMU and DMA
> + masters. Therefore, the PCI root complex that hosts the virtio-iommu
> + contains a child node representing the IOMMU device explicitly.
> +
> + DMA from the IOMMU device isn't managed by another IOMMU. Therefore the
> + virtio-iommu node doesn't have an "iommus" property, and is omitted from
> + the iommu-map property of the root complex.
> +
> +properties:
> + # If compatible is present, it should contain the vendor and device ID
> + # according to the PCI Bus Binding specification. Since PCI provides
> + # built-in identification methods, compatible is not actually required.
> + compatible:
> + oneOf:
> + - items:
> + - const: virtio,pci-iommu
> + - const: pci1af4,1057
> + - items:
> + - const: pci1af4,1057
> +
> + reg:
> + description: |
> + PCI address of the IOMMU. As defined in the PCI Bus Binding
> + reference, the reg property is a five-cell address encoded as (phys.hi
> + phys.mid phys.lo size.hi size.lo). phys.hi should contain the device's
> + BDF as 0b00000000 bbbbbbbb dddddfff 00000000. The other cells should be
> + zero. See Documentation/devicetree/bindings/pci/pci.txt
> +
> + '#iommu-cells':
> + const: 1
> +
> +required:
Also: compatible
> + - reg
> + - '#iommu-cells'
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + pcie0 {
Node name: pcie
> + #address-cells = <3>;
> + #size-cells = <2>;
> +
device_type and then you will see a bunch of warnings.
> + /*
> + * The IOMMU manages all functions in this PCI domain except
> + * itself. Omit BDF 00:01.0.
> + */
> + iommu-map = <0x0 &iommu0 0x0 0x8
> + 0x9 &iommu0 0x9 0xfff7>;
> +
> + /* The IOMMU programming interface uses slot 00:01.0 */
> + iommu0: iommu@1,0 {
> + compatible = "pci1af4,1057";
> + reg = <0x800 0 0 0 0>;
> + #iommu-cells = <1>;
> + };
> + };
> +
> + pcie1 {
Node name: pcie (so probably you will need unit address and reg)
> + /*
> + * The IOMMU also manages all functions from this domain,
> + * with endpoint IDs 0x10000 - 0x1ffff
> + */
> + iommu-map = <0x0 &iommu0 0x10000 0x10000>;
> + };
> +
> + ethernet {
> + /* The IOMMU manages this platform device with endpoint ID 0x20000 */
> + iommus = <&iommu0 0x20000>;
> + };
> +
> +...
Best regards,
Krzysztof
