2022-09-23 08:46:18

by Jean-Philippe Brucker

[permalink] [raw]
Subject: [PATCH v3] dt-bindings: virtio: Convert virtio,pci-iommu to DT schema

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 <[email protected]>
---
v3: Renamed file and type to pci-iommu
v2: https://lore.kernel.org/linux-devicetree/[email protected]/
---
.../devicetree/bindings/virtio/iommu.txt | 66 ------------
.../devicetree/bindings/virtio/pci-iommu.yaml | 101 ++++++++++++++++++
2 files changed, 101 insertions(+), 66 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/virtio/iommu.txt
create mode 100644 Documentation/devicetree/bindings/virtio/pci-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:
-
[email protected] {
- compatible = "pci-host-ecam-generic";
- ...
-
- /* The IOMMU programming interface uses slot 00:01.0 */
- iommu0: [email protected] {
- 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>;
-};
-
[email protected] {
- 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>;
-};
-
[email protected] {
- ...
- /* 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/pci-iommu.yaml b/Documentation/devicetree/bindings/virtio/pci-iommu.yaml
new file mode 100644
index 000000000000..972a785a42de
--- /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 <[email protected]>
+
+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>;
+
+ [email protected] {
+ 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: [email protected],0 {
+ compatible = "pci1af4,1057";
+ reg = <0x800 0 0 0 0>;
+ #iommu-cells = <1>;
+ };
+ };
+
+ [email protected] {
+ 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>;
+ };
+ };
+
+...
--
2.37.3


2022-09-23 10:02:46

by Krzysztof Kozlowski

[permalink] [raw]
Subject: Re: [PATCH v3] dt-bindings: virtio: Convert virtio,pci-iommu to DT schema

On 23/09/2022 09:44, 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 <[email protected]>


Reviewed-by: Krzysztof Kozlowski <[email protected]>

Best regards,
Krzysztof

2022-09-26 19:16:50

by Rob Herring

[permalink] [raw]
Subject: Re: [PATCH v3] dt-bindings: virtio: Convert virtio,pci-iommu to DT schema

On Fri, 23 Sep 2022 08:44:38 +0100, 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 <[email protected]>
> ---
> v3: Renamed file and type to pci-iommu
> v2: https://lore.kernel.org/linux-devicetree/[email protected]/
> ---
> .../devicetree/bindings/virtio/iommu.txt | 66 ------------
> .../devicetree/bindings/virtio/pci-iommu.yaml | 101 ++++++++++++++++++
> 2 files changed, 101 insertions(+), 66 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/virtio/iommu.txt
> create mode 100644 Documentation/devicetree/bindings/virtio/pci-iommu.yaml
>

Applied, thanks!