[v5,0/2] Driver for Open Profile for DICE

Open Profile for DICE is an open protocol for measured boot compatible
with the Trusted Computing Group's Device Identifier Composition
Engine (DICE) specification. The generated Compound Device Identifier
(CDI) certificates represent the measured hardware/software combination
and can be used by userspace for remote attestation and sealing.

This patchset adds DeviceTree bindings for the DICE device referencing
a reserved memory region containing the CDIs, and a driver that exposes
the memory region to userspace via a misc device.

See https://pigweed.googlesource.com/open-dice for more details.

The patches are based on top of v5.16-rc6 and can also be found here:
  https://android-kvm.googlesource.com/linux topic/dice_v5

Changes since v4:
  * registered compatible in 'reserved_mem_matches'
  * removed unnecessary DT node, only reserved-memory
  * fixed typos in comments

Changes since v3:
  * align with semantics of read/write
  * fix kerneldoc warnings
  * fix printf format warnings

Changes since v2:
  * renamed from 'dice' to 'open-dice'
  * replaced ioctls with read/write
  * replaced memzero_explicit with memset
  * allowed multiple instances
  * expanded Kconfig description

Changes since v1:
  * converted to miscdevice
  * all mappings now write-combine to simplify semantics
  * removed atomic state, any attempt at exclusive access
  * simplified wipe, applied on ioctl, not on release
  * fixed ioctl return value


David Brazdil (2):
  dt-bindings: reserved-memory: Open Profile for DICE
  misc: open-dice: Add driver to expose DICE data to userspace

 .../reserved-memory/google,open-dice.yaml     |  45 +++++
 drivers/misc/Kconfig                          |  12 ++
 drivers/misc/Makefile                         |   1 +
 drivers/misc/open-dice.c                      | 188 ++++++++++++++++++
 drivers/of/platform.c                         |   1 +
 5 files changed, 247 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml
 create mode 100644 drivers/misc/open-dice.c

--
2.34.1.307.g9b7440fafd-goog

On Tue, Dec 21, 2021 at 05:45:01PM +0000, David Brazdil wrote:
> Add DeviceTree bindings for Open Profile for DICE, an open protocol for
> measured boot. Firmware uses DICE to measure the hardware/software
> combination and generates Compound Device Identifier (CDI) certificates.
> These are stored in memory and the buffer is described in the DT as
> a reserved memory region compatible with 'google,open-dice'.
> 
> Signed-off-by: David Brazdil <dbrazdil@google.com>
> ---
>  .../reserved-memory/google,open-dice.yaml     | 45 +++++++++++++++++++
>  1 file changed, 45 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml
> 
> diff --git a/Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml b/Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml
> new file mode 100644
> index 000000000000..7bc714e9715f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reserved-memory/google,open-dice.yaml
> @@ -0,0 +1,45 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/reserved-memory/google,open-dice.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Open Profile for DICE Device Tree Bindings
> +
> +description: |
> +  This binding represents a reserved memory region containing data
> +  generated by the Open Profile for DICE protocol.
> +
> +  See https://pigweed.googlesource.com/open-dice/
> +
> +maintainers:
> +  - David Brazdil <dbrazdil@google.com>
> +
> +allOf:
> +  - $ref: "reserved-memory.yaml"
> +
> +properties:
> +  compatible:
> +    const: google,open-dice
> +
> +  reg:
> +    description: page-aligned region of memory containing DICE data
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: true

unevaluatedProperties: false

Additional properties are only allowed for common schema included by 
other schemas.

> +
> +examples:
> +  - |
> +    reserved-memory {
> +        #address-cells = <2>;
> +        #size-cells = <1>;
> +
> +        dice: dice@12340000 {
> +            compatible = "google,open-dice";
> +            reg = <0x00 0x12340000 0x2000>;
> +            no-map;
> +        };
> +    };
> -- 
> 2.34.1.307.g9b7440fafd-goog
> 
>