On Fri, Aug 30, 2024 at 10:20 AM Krzysztof Kozlowski <k...@kernel.org> wrote:
>
> On Fri, Aug 30, 2024 at 09:03:50AM +0200, Jens Wiklander wrote:
> > From: Olivier Masse <olivier.ma...@nxp.com>
> >
> > DMABUF reserved memory definition for OP-TEE secure data path feature.
> >
> > Signed-off-by: Olivier Masse <olivier.ma...@nxp.com>
> > Signed-off-by: Jens Wiklander <jens.wiklan...@linaro.org>
> > ---
> > .../linaro,restricted-heap.yaml | 56 +++++++++++++++++++
> > 1 file changed, 56 insertions(+)
> > create mode 100644
> > Documentation/devicetree/bindings/reserved-memory/linaro,restricted-heap.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/reserved-memory/linaro,restricted-heap.yaml
> >
> > b/Documentation/devicetree/bindings/reserved-memory/linaro,restricted-heap.yaml
> > new file mode 100644
> > index 000000000000..0ab87cf02775
> > --- /dev/null
> > +++
> > b/Documentation/devicetree/bindings/reserved-memory/linaro,restricted-heap.yaml
> > @@ -0,0 +1,56 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id:
> > http://devicetree.org/schemas/reserved-memory/linaro,restricted-heap.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Linaro Secure DMABUF Heap
> > +
> > +maintainers:
> > + - Olivier Masse <olivier.ma...@nxp.com>
> > +
> > +description:
> > + Linaro OP-TEE firmware needs a reserved memory for the
> > + Secure Data Path feature (aka SDP).
> > + The purpose is to provide a restricted memory heap which allow
> > + the normal world OS (REE) to allocate/free restricted buffers.
> > + The TEE is reponsible for protecting the SDP memory buffers.
> > + TEE Trusted Application can access restricted memory references
> > + provided as parameters (DMABUF file descriptor).
>
> And what is the difference from regular reserved memory? Why it cannot
> be used?
Good question. I need a compatible = "linaro,restricted-heap" to find
it, but it appears that's permitted with regular reserved memory.
Let's drop this patch. Thanks for pointing me in the right direction.
>
> > +
> > +allOf:
> > + - $ref: "reserved-memory.yaml"
>
> It does not look like you tested the bindings, at least after quick
> look. Please run (see
> Documentation/devicetree/bindings/writing-schema.rst for instructions).
> Maybe you need to update your dtschema and yamllint.
You're right, sorry.
>
> > +
> > +properties:
> > + compatible:
> > + const: linaro,restricted-heap
> > +
> > + reg:
> > + description:
> > + Region of memory reserved for OP-TEE SDP feature
> > +
> > + no-map:
> > + $ref: /schemas/types.yaml#/definitions/flag
> > + description:
> > + Avoid creating a virtual mapping of the region as part of the OS'
> > + standard mapping of system memory.
> > +
> > +unevaluatedProperties: false
>
> This goes after "required:" block.
OK
>
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - no-map
> > +
> > +examples:
> > + - |
> > + reserved-memory {
> > + #address-cells = <2>;
> > + #size-cells = <2>;
> > +
> > + sdp@3e800000 {
> > + compatible = "linaro,restricted-heap";
> > + no-map;
> > + reg = <0 0x3E800000 0 0x00400000>;
>
> lowercase hex
>
OK
Thanks,
Jens
> Best regards,
> Krzysztof
>
