Add YAML devicetree binding for the MbedTEE Trusted Execution Environment driver.
The binding covers two platform configurations: - ARM/AArch64 (TrustZone, SMC): two reserved-memory regions (rpc-t2r-ring and rpc-t2r-shm) plus a GIC SPI edge interrupt for TEE-to-REE notifications. - RISC-V (IMSIC): three reserved-memory regions, adding rpc-r2t-ring for REE-to-TEE command submissions; no interrupts property (T2R notifications use IMSIC MSI allocated at runtime).
Signed-off-by: Xing Loong xing.xl.loong@gmail.com --- .../bindings/firmware/mbedtee,rpc.yaml | 221 ++++++++++++++++++ 1 file changed, 221 insertions(+) create mode 100644 Documentation/devicetree/bindings/firmware/mbedtee,rpc.yaml
diff --git a/Documentation/devicetree/bindings/firmware/mbedtee,rpc.yaml b/Documentation/devicetree/bindings/firmware/mbedtee,rpc.yaml new file mode 100644 index 0000000..08ae255 --- /dev/null +++ b/Documentation/devicetree/bindings/firmware/mbedtee,rpc.yaml @@ -0,0 +1,221 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/firmware/mbedtee,rpc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: MbedTEE Trusted Execution Environment + +maintainers: + - Xing Loong xing.xl.loong@gmail.com + +description: | + MbedTEE is a Trusted Execution Environment for embedded systems. + This binding describes the shared-memory regions used for RPC + communication between the Linux REE driver and MbedTEE OS. + + The REE and TEE CPUs sharing the RPC memory must be in a + hardware-coherent domain (same CPU cluster, coherent caches). + + Two or three reserved-memory regions are required: + + rpc-t2r-ring ring buffer for TEE-to-REE notifications (all platforms) + rpc-t2r-shm shared memory for TEE-to-REE RPC payloads (all platforms) + rpc-r2t-ring ring buffer for REE-to-TEE command submissions (RISC-V only) + + On ARM/AArch64 the transport uses SMC calls; TEE-to-REE + notifications use a GIC SPI edge interrupt. + + On RISC-V the TEE notifies the REE via IMSIC MSI; the REE submits + commands via shared-memory rpc-r2t-ring that the TEE polls. No + REE-to-TEE interrupt is used. No SBI ecall is involved. + +properties: + $nodename: + const: mbedtee + + compatible: + const: mbedtee,rpc + + interrupts: + description: + GIC interrupt used by the TEE to notify the REE of pending RPC + responses (ARM/AArch64 only). Not present on RISC-V platforms which + use IMSIC platform MSI interrupts allocated dynamically at runtime. + + msi-parent: + maxItems: 1 + description: + IMSIC MSI controller used by the Linux driver to allocate the + TEE-to-REE notification interrupt on RISC-V platforms. Not present on + ARM/AArch64 platforms, which use the interrupts property. + + memory-region: + minItems: 2 + maxItems: 3 + description: + References to reserved-memory regions for REE<->TEE communication. + Entries must match memory-region-names order. + + memory-region-names: + minItems: 2 + maxItems: 3 + items: + enum: + - rpc-t2r-ring + - rpc-t2r-shm + - rpc-r2t-ring + +required: + - compatible + +allOf: + - if: + required: + - interrupts + then: + required: + - interrupts + - memory-region + - memory-region-names + properties: + msi-parent: false + memory-region: + minItems: 2 + maxItems: 2 + memory-region-names: + items: + - const: rpc-t2r-ring + - const: rpc-t2r-shm + else: + required: + - msi-parent + - memory-region + - memory-region-names + properties: + memory-region: + minItems: 3 + maxItems: 3 + memory-region-names: + items: + - const: rpc-t2r-ring + - const: rpc-t2r-shm + - const: rpc-r2t-ring + +additionalProperties: false + +examples: + - | + /* ARM TrustZone (SMC) */ + #include <dt-bindings/interrupt-controller/arm-gic.h> + / { + #address-cells = <2>; + #size-cells = <2>; + + gic: interrupt-controller@2f000000 { + compatible = "arm,gic-v3"; + reg = <0 0x2f000000 0 0x10000>, + <0 0x2f100000 0 0x200000>; + interrupt-controller; + #interrupt-cells = <3>; + }; + + reserved-memory { + #address-cells = <2>; + #size-cells = <2>; + ranges; + + mbedtee_t2r_ring: rpc-t2r-ring@85f10000 { + reg = <0 0x85f10000 0 0x20000>; + no-map; + }; + + mbedtee_t2r_shm: rpc-t2r-shm@85f30000 { + reg = <0 0x85f30000 0 0x40000>; + no-map; + }; + }; + + firmware { + mbedtee { + compatible = "mbedtee,rpc"; + interrupt-parent = <&gic>; + interrupts = <GIC_SPI 72 IRQ_TYPE_EDGE_RISING>; + memory-region = <&mbedtee_t2r_ring>, <&mbedtee_t2r_shm>; + memory-region-names = "rpc-t2r-ring", "rpc-t2r-shm"; + }; + }; + }; + + - | + /* RISC-V IMSIC (ring-buffer polling REE->TEE, MSI TEE->REE) */ + / { + #address-cells = <2>; + #size-cells = <2>; + + cpus { + #address-cells = <1>; + #size-cells = <0>; + + cpu@0 { + device_type = "cpu"; + reg = <0>; + + cpu0_intc: interrupt-controller { + compatible = "riscv,cpu-intc"; + interrupt-controller; + #interrupt-cells = <1>; + }; + }; + }; + + imsic: interrupt-controller@28000000 { + compatible = "qemu,imsics", "riscv,imsics"; + reg = <0 0x28000000 0 0x1000>; + interrupts-extended = <&cpu0_intc 9>; + interrupt-controller; + #interrupt-cells = <0>; + msi-controller; + #msi-cells = <0>; + riscv,num-ids = <255>; + }; + + reserved-memory { + #address-cells = <2>; + #size-cells = <2>; + ranges; + + rv_t2r_ring: rpc-t2r-ring@5f10000 { + reg = <0 0x5f10000 0 0x20000>; + no-map; + }; + + rv_t2r_shm: rpc-t2r-shm@5f30000 { + reg = <0 0x5f30000 0 0x40000>; + no-map; + }; + + rv_r2t_ring: rpc-r2t-ring@5f70000 { + reg = <0 0x5f70000 0 0x20000>; + no-map; + }; + }; + + /* + * The riscv container avoids a duplicate /firmware/mbedtee path + * with the ARM example above when the DT checker concatenates + * examples into a single .dts. + */ + riscv { + firmware { + mbedtee { + compatible = "mbedtee,rpc"; + msi-parent = <&imsic>; + memory-region = <&rv_t2r_ring>, <&rv_t2r_shm>, + <&rv_r2t_ring>; + memory-region-names = "rpc-t2r-ring", "rpc-t2r-shm", + "rpc-r2t-ring"; + }; + }; + }; + };