[PATCH v4 1/7] dt-bindings: iommu: riscv: Add bindings for RISC-V IOMMU

[Tomasz Jeznach]

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>
Reviewed-by: Conor Dooley <conor.dooley at microchip.com>
Signed-off-by: Tomasz Jeznach <tjeznach at rivosinc.com>
---
 .../bindings/iommu/riscv,iommu.yaml           | 147 ++++++++++++++++++
 MAINTAINERS                                   |   7 +
 2 files changed, 154 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..5d015eeb06d0
--- /dev/null
+++ b/Documentation/devicetree/bindings/iommu/riscv,iommu.yaml
@@ -0,0 +1,147 @@
+# 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,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.
+
+  '#iommu-cells':
+    const: 1
+    description:
+      The single cell describes the requester id emitted 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,riscv-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,riscv-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,riscv-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>;
+
+            /* 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