xref: /kernel/linux/linux-5.10/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml

# SPDX-License-Identifier: GPL-2.0-only
%YAML 1.2
---
$id: http://devicetree.org/schemas/iommu/arm,smmu-v3.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: ARM SMMUv3 Architecture Implementation

maintainers:
  - Will Deacon <will@kernel.org>
  - Robin Murphy <Robin.Murphy@arm.com>

description: |+
  The SMMUv3 architecture is a significant departure from previous
  revisions, replacing the MMIO register interface with in-memory command
  and event queues and adding support for the ATS and PRI components of
  the PCIe specification.

properties:
  $nodename:
    pattern: "^iommu@[0-9a-f]*"
  compatible:
    const: arm,smmu-v3

  reg:
    maxItems: 1

  interrupts:
    minItems: 1
    maxItems: 4

  interrupt-names:
    oneOf:
      - const: combined
        description:
          The combined interrupt is optional, and should only be provided if the
          hardware supports just a single, combined interrupt line.
          If provided, then the combined interrupt will be used in preference to
          any others.
      - minItems: 2
        maxItems: 4
        items:
          - const: eventq     # Event Queue not empty
          - const: gerror     # Global Error activated
          - const: priq       # PRI Queue not empty
          - const: cmdq-sync  # CMD_SYNC complete

  '#iommu-cells':
    const: 1

  dma-coherent:
    description: |
      Present if page table walks made by the SMMU are cache coherent with the
      CPU.

      NOTE: this only applies to the SMMU itself, not masters connected
      upstream of the SMMU.

  msi-parent: true

  hisilicon,broken-prefetch-cmd:
    type: boolean
    description: Avoid sending CMD_PREFETCH_* commands to the SMMU.

  cavium,cn9900-broken-page1-regspace:
    type: boolean
    description:
      Replaces all page 1 offsets used for EVTQ_PROD/CONS, PRIQ_PROD/CONS
      register access with page 0 offsets. Set for Cavium ThunderX2 silicon that
      doesn't support SMMU page1 register space.

required:
  - compatible
  - reg
  - '#iommu-cells'

additionalProperties: false

examples:
  - |+
    #include <dt-bindings/interrupt-controller/arm-gic.h>
    #include <dt-bindings/interrupt-controller/irq.h>

    iommu@2b400000 {
            compatible = "arm,smmu-v3";
            reg = <0x2b400000 0x20000>;
            interrupts = <GIC_SPI 74 IRQ_TYPE_EDGE_RISING>,
                         <GIC_SPI 75 IRQ_TYPE_EDGE_RISING>,
                         <GIC_SPI 77 IRQ_TYPE_EDGE_RISING>,
                         <GIC_SPI 79 IRQ_TYPE_EDGE_RISING>;
            interrupt-names = "eventq", "gerror", "priq", "cmdq-sync";
            dma-coherent;
            #iommu-cells = <1>;
            msi-parent = <&its 0xff0000>;
    };