[PATCH 1/9] dt-bindings: Arm: Add Firmware Framework for Armv8-A (FF-A) binding
Rob Herring
robh at kernel.org
Wed Sep 2 18:14:13 EDT 2020
On Sat, Aug 29, 2020 at 06:09:15PM +0100, Sudeep Holla wrote:
> From: Will Deacon <will at kernel.org>
>
> Add devicetree bindings for a FF-A-compliant hypervisor, its partitions
> and their memory regions. The naming is ludicrous but also not by fault.
>
> Signed-off-by: Will Deacon <will at kernel.org>
> (sudeep.holla: Dropped PSA from name and elsewhere as it seem to have
> disappeared mysteriously just before the final release)
> Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
> ---
> .../devicetree/bindings/arm/arm,ffa.yaml | 102 ++++++++++++++++++
> .../reserved-memory/arm,ffa-memory.yaml | 71 ++++++++++++
> 2 files changed, 173 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/arm,ffa.yaml
> create mode 100644 Documentation/devicetree/bindings/reserved-memory/arm,ffa-memory.yaml
>
> diff --git a/Documentation/devicetree/bindings/arm/arm,ffa.yaml b/Documentation/devicetree/bindings/arm/arm,ffa.yaml
> new file mode 100644
> index 000000000000..668a5995fcab
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/arm,ffa.yaml
> @@ -0,0 +1,102 @@
> +# SPDX-License-Identifier: GPL-2.0
Dual license new bindings:
(GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/arm,ffa.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Arm Firmware Framework for Arm v8-A
> +
> +maintainers:
> + - Will Deacon <will at kernel.org>
> +
> +description: |
> + Firmware frameworks implementing partition setup according to the FF-A
> + specification defined by ARM document number ARM DEN 0077A ("Arm Firmware
> + Framework for Arm v8-A") [0] must provide a "manifest and image" for each
> + partition to the "partition manager" so that the partition execution contexts
> + can be initialised.
> +
> + In the case of a virtual FFA instance, the manifest and image details can be
> + passed to the hypervisor (e.g. Linux KVM) using this binding.
> +
> + [0] https://developer.arm.com/docs/den0077/latest
There's efforts to define 'system DT' describing all the CPUs in a
system (such as both A and R cores) as well as physical partitioning.
I'm not sure that virtual partitioning would need a different binding.
Or at least there's probably some overlap.
> +
> +properties:
> + $nodename:
> + const: ffa_hyp
> +
> + compatible:
> + oneOf:
> + - const: arm,ffa-1.0-hypervisor
> +
> + memory-region:
> + $ref: '/schemas/types.yaml#/definitions/phandle'
> + description: |
> + A phandle to the reserved memory region [1] to be used by the hypervisor.
> + The reserved memory region must be compatible with
> + "arm,ffa-1.0-hypervisor-memory-region".
> +
> + [1] Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
> +
> +patternProperties:
> + "^ffa_partition[0-9]+$":
s/_/-/
Probably should use 'reg' to number partitions. Is the numbering
significant?
> + type: object
> + description: One or more child nodes, each describing an FFA partition.
> + properties:
> + $nodename:
> + const: ffa_partition
> +
> + compatible:
> + oneOf:
> + - const: arm,ffa-1.0-partition
> +
> + uuid:
> + $ref: '/schemas/types.yaml#definitions/string'
json-schema can do better here:
format: uuid
Though 'format' will need to be allowed in our meta-schema.
> + description: |
> + The 128-bit UUID [2] of the service implemented by this partition.
> +
> + [2] https://tools.ietf.org/html/rfc4122
> +
> + nr-exec-ctxs:
> + $ref: '/schemas/types.yaml#/definitions/uint32'
> + description: |
> + The number of virtual CPUs to instantiate for this partition.
Just 'nr-cpus' would be clearer in my opinion.
What happens on big.LITTLE?
> +
> + exec-state:
> + description: The execution state in which to execute the partition.
> + oneOf:
> + - const: "AArch64"
> + - const: "AArch32"
Why is this needed? We don't need anything like this for KVM today.
> +
> + entry-point:
> + $ref: '/schemas/types.yaml#/definitions/uint32-matrix'
> + description: |
> + The entry address of the partition specified as an Intermediate
> + Physical Address (IPA) encoded according to the '#address-cells'
> + property.
Is the address unique or you could have the same image for multiple
partitions? If unique, then you could use 'reg' here.
You didn't document using '#address-cells'. Really, I'd just make this a
fixed uint64 (if not 'reg').
> +
> + memory-region:
> + $ref: '/schemas/types.yaml#/definitions/phandle-array'
> + description: |
> + A list of phandles to FFA reserved memory regions [3] for this
> + partition.
> +
> + [3] Documentation/devicetree/bindings/reserved-memory/arm,ffa-memory.yaml
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + ffa_hyp {
> + compatible = "arm,ffa-1.0-hypervisor";
> + memory-region = <&ffa_hyp_reserved>;
> +
> + ffa_partition0 {
> + compatible = "arm,ffa-1.0-partition";
> + uuid = "12345678-9abc-def0-1234-56789abcdef0";
> + nr-exec-ctxs = <2>;
> + exec-state = "AArch64";
> + entry-point = <0x80000>;
> + memory-region = <&ffa_reserved0 &ffa_reserved1>;
> + };
> + };
> diff --git a/Documentation/devicetree/bindings/reserved-memory/arm,ffa-memory.yaml b/Documentation/devicetree/bindings/reserved-memory/arm,ffa-memory.yaml
> new file mode 100644
> index 000000000000..5335e07abcfc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reserved-memory/arm,ffa-memory.yaml
> @@ -0,0 +1,71 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/reserved-memory/arm,ffa-memory.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Memory Region for Arm Firmware Framework for Arm v8-A
> +
> +maintainers:
> + - Will Deacon <will at kernel.org>
> +
> +description: |
> + This binding allows a FF-A implementation to describe the normal memory
> + regions of a partition [1] to a hypervisor according to [2].
> +
> + The physical address range reserved for the partition can be specified as a
> + static allocation using the 'reg' property or as a dynamic allocation using
> + the 'size' property. If both properties are omitted, then the hypervisor can
> + allocate physical memory for the partition however it sees fit.
> +
> + [1] Documentation/devicetree/bindings/arm/arm,ffa.yaml
> + [2] Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
> +
> +properties:
> + $nodename:
> + pattern: "^ffa_mem(@[0-9a-f]+)?$"
> +
> + compatible:
> + oneOf:
> + - const: arm,ffa-1.0-partition-memory-region
> +
> + ipa-range:
> + $ref: '/schemas/types.yaml#/definitions/uint32-matrix'
> + description: |
> + The Intermediate Physical Address (IPA) range (encoded in the same way as
> + a 'reg' property) at which to map the physical memory. If the IPA range is
> + larger than the physical memory region then the region is mapped starting
> + at the base of the IPA range.
> +
> + read-only:
> + type: boolean
> + description: |
> + (static allocation only) The memory region has been pre-populated
> + by the firmware framework and must be mapped without write permission
> + at stage 2.
> +
> + non-executable:
> + type: boolean
> + description: |
> + The memory region must be mapped without execute permission at stage 2.
> +
> +
> +required:
> + - compatible
> +
> +# The "reserved-memory" binding defines additional properties.
> +additionalProperties: true
> +
> +examples:
> + - |
> + reserved-memory {
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + ffa_reserved0: ffa_mem at 100000000 {
> + compatible = "arm,ffa-1.0-partition-memory-region";
> + reg = <0x1 0x0 0x0 0x04000000>; // 64M @ 1GB
> + ipa-range = <0x0 0x0 0x0 0x04000000>; // 64M @ 0x0
So we need the PA and IPA? We're using DT to define stage 2 page
tables...
> + read-only;
> + };
> + };
> --
> 2.17.1
>
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