[PATCH v3 1/7] dt-bindings: iommu: riscv: Add bindings for RISC-V IOMMU
Rob Herring
robh at kernel.org
Wed May 1 06:15:56 PDT 2024
On Tue, Apr 30, 2024 at 01:01:51PM -0700, Tomasz Jeznach wrote:
> Add bindings for the RISC-V IOMMU device drivers.
>
> Co-developed-by: Anup Patel <apatel at ventanamicro.com>
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> Signed-off-by: Tomasz Jeznach <tjeznach at rivosinc.com>
> ---
> .../bindings/iommu/riscv,iommu.yaml | 150 ++++++++++++++++++
> MAINTAINERS | 7 +
> 2 files changed, 157 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
>
> diff --git a/Documentation/devicetree/bindings/iommu/riscv,iommu.yaml b/Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
> new file mode 100644
> index 000000000000..16817525e157
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
> @@ -0,0 +1,150 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iommu/riscv,iommu.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: RISC-V IOMMU Architecture Implementation
> +
> +maintainers:
> + - Tomasz Jeznach <tjeznach at rivosinc.com>
> +
> +description: |
> + The RISC-V IOMMU provides memory address translation and isolation for
> + input and output devices, supporting per-device translation context,
> + shared process address spaces including the ATS and PRI components of
> + the PCIe specification, two stage address translation and MSI remapping.
> + It supports identical translation table format to the RISC-V address
> + translation tables with page level access and protection attributes.
> + Hardware uses in-memory command and fault reporting queues with wired
> + interrupt or MSI notifications.
> +
> + Visit https://github.com/riscv-non-isa/riscv-iommu for more details.
> +
> + For information on assigning RISC-V IOMMU to its peripheral devices,
> + see generic IOMMU bindings.
> +
> +properties:
> + # For PCIe IOMMU hardware compatible property 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. For non-PCIe hardware implementations 'riscv,iommu'
> + # should be specified along with 'reg' property providing MMIO location.
> + compatible:
> + oneOf:
> + - items:
> + - enum:
> + - qemu,iommu
'qemu,iommu' is too broad. Could be other QEMU implementations of an
IOMMU. So 'qemu,riscv-iommu'.
> + - const: riscv,iommu
> + - items:
> + - enum:
> + - pci1efd,edf1
> + - const: riscv,pci-iommu
> +
> + reg:
> + maxItems: 1
> + description:
> + For non-PCI devices this represents base address and size of for the
> + IOMMU memory mapped registers interface.
> + For PCI IOMMU hardware implementation this should represent an 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), where phys.hi should contain the device's BDF as
> + 0b00000000 bbbbbbbb dddddfff 00000000. The other cells should be zero.
No need to describe what the PCI address looks like.
> +
> + '#iommu-cells':
> + const: 1
> + description:
> + Has to be one. The single cell describes the requester id emitted
Drop 'Has to be one'. You already said that with the schema.
> + by a master to the IOMMU.
> +
> + interrupts:
> + minItems: 1
> + maxItems: 4
> + description:
> + Wired interrupt vectors available for RISC-V IOMMU to notify the
> + RISC-V HARTS. The cause to interrupt vector is software defined
> + using IVEC IOMMU register.
> +
> + msi-parent: true
> +
> + power-domains:
> + maxItems: 1
> +
> +required:
> + - compatible
> + - reg
> + - '#iommu-cells'
> +
> +additionalProperties: false
> +
> +examples:
> + - |+
> + /* Example 1 (IOMMU device with wired interrupts) */
> + #include <dt-bindings/interrupt-controller/irq.h>
> +
> + iommu1: iommu at 1bccd000 {
> + compatible = "qemu,iommu", "riscv,iommu";
> + reg = <0x1bccd000 0x1000>;
> + interrupt-parent = <&aplic_smode>;
> + interrupts = <32 IRQ_TYPE_LEVEL_HIGH>,
> + <33 IRQ_TYPE_LEVEL_HIGH>,
> + <34 IRQ_TYPE_LEVEL_HIGH>,
> + <35 IRQ_TYPE_LEVEL_HIGH>;
> + #iommu-cells = <1>;
> + };
> +
> + /* Device with two IOMMU device IDs, 0 and 7 */
> + master1 {
> + iommus = <&iommu1 0>, <&iommu1 7>;
> + };
> +
> + - |+
> + /* Example 2 (IOMMU device with shared wired interrupt) */
> + #include <dt-bindings/interrupt-controller/irq.h>
> +
> + iommu2: iommu at 1bccd000 {
> + compatible = "qemu,iommu", "riscv,iommu";
> + reg = <0x1bccd000 0x1000>;
> + interrupt-parent = <&aplic_smode>;
> + interrupts = <32 IRQ_TYPE_LEVEL_HIGH>;
> + #iommu-cells = <1>;
> + };
> +
> + - |+
> + /* Example 3 (IOMMU device with MSIs) */
> + iommu3: iommu at 1bcdd000 {
> + compatible = "qemu,iommu", "riscv,iommu";
> + reg = <0x1bccd000 0x1000>;
> + msi-parent = <&imsics_smode>;
> + #iommu-cells = <1>;
> + };
> +
> + - |+
> + /* Example 4 (IOMMU PCIe device with MSIs) */
> + bus {
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + pcie at 30000000 {
> + device_type = "pci";
> + #address-cells = <3>;
> + #size-cells = <2>;
> + reg = <0x0 0x30000000 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>;
Bracket each entry.
> +
> + /* The IOMMU programming interface uses slot 00:01.0 */
> + iommu0: iommu at 1,0 {
> + compatible = "pci1efd,edf1", "riscv,pci-iommu";
> + reg = <0x800 0 0 0 0>;
> + #iommu-cells = <1>;
> + };
> + };
> + };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f6dc90559341..7fcf7c27ef6b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -18958,6 +18958,13 @@ F: arch/riscv/
> N: riscv
> K: riscv
>
> +RISC-V IOMMU
> +M: Tomasz Jeznach <tjeznach at rivosinc.com>
> +L: iommu at lists.linux.dev
> +L: linux-riscv at lists.infradead.org
> +S: Maintained
> +F: Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
> +
> RISC-V MICROCHIP FPGA SUPPORT
> M: Conor Dooley <conor.dooley at microchip.com>
> M: Daire McNamara <daire.mcnamara at microchip.com>
> --
> 2.34.1
>
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