diff options
Diffstat (limited to 'Documentation/devicetree/bindings/virtio/pci-iommu.yaml')
| -rw-r--r-- | Documentation/devicetree/bindings/virtio/pci-iommu.yaml | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/virtio/pci-iommu.yaml b/Documentation/devicetree/bindings/virtio/pci-iommu.yaml new file mode 100644 index 000000000..972a785a4 --- /dev/null +++ b/Documentation/devicetree/bindings/virtio/pci-iommu.yaml @@ -0,0 +1,101 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/virtio/pci-iommu.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: virtio-iommu device using the virtio-pci transport + +maintainers: + - Jean-Philippe Brucker <jean-philippe@linaro.org> + +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: + - compatible + - reg + - '#iommu-cells' + +additionalProperties: false + +examples: + - | + bus { + #address-cells = <2>; + #size-cells = <2>; + + pcie@40000000 { + device_type = "pci"; + #address-cells = <3>; + #size-cells = <2>; + reg = <0x0 0x40000000 0x0 0x1000000>; + ranges = <0x02000000 0x0 0x41000000 0x0 0x41000000 0x0 0x0f000000>; + + /* + * 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>; + }; + }; + + pcie@50000000 { + device_type = "pci"; + #address-cells = <3>; + #size-cells = <2>; + reg = <0x0 0x50000000 0x0 0x1000000>; + ranges = <0x02000000 0x0 0x51000000 0x0 0x51000000 0x0 0x0f000000>; + + /* + * 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>; + }; + }; + +... |