Hi Brian, It was part of a discussion during a Devicetree evolution meeting with Bill Mills from Linaro. I've done some modification to OPTEE OS and OPTEE TEST to support dma buf: OPTEE OS https://github.com/OP-TEE/optee_os/commit/eb108a04369fbfaf60c03c0e00bbe9489a761c69 https://github.com/OP-TEE/optee_os/commit/513b0748d46e7eefa17dadb204289e49dc17f854 OPTEE TEST https://github.com/OP-TEE/optee_test/commit/da5282a011b40621a2cf7a296c11a35c833ed91b BR / Olivier On ven., 2022-08-05 at 16:46 +0100, Brian Starkey wrote: > Caution: EXT Email > > +Rob and devicetree list. > > I don't know if this should be "linaro" or something more generic, > and also where previous discussions got to about DMA heaps in DT. > > Cheers, > -Brian > > On Fri, Aug 05, 2022 at 03:53:29PM +0200, Olivier Masse wrote: > > DMABUF Reserved memory definition for OP-TEE SDP feaure. > > > > Signed-off-by: Olivier Masse <olivier.masse@xxxxxxx> > > --- > > .../reserved-memory/linaro,secure-heap.yaml | 56 > > +++++++++++++++++++ > > 1 file changed, 56 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/reserved- > > memory/linaro,secure-heap.yaml > > > > diff --git a/Documentation/devicetree/bindings/reserved- > > memory/linaro,secure-heap.yaml > > b/Documentation/devicetree/bindings/reserved-memory/linaro,secure- > > heap.yaml > > new file mode 100644 > > index 000000000000..80522a4e2989 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/reserved- > > memory/linaro,secure-heap.yaml > > @@ -0,0 +1,56 @@ > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: > > https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevicetree.org%2Fschemas%2Freserved-memory%2Flinaro%2Csecure-heap.yaml%23&data=05%7C01%7Colivier.masse%40nxp.com%7C0a9e67bbd65446aa05e408da76f9b82a%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637953112157450452%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=lb9U8Fnt1Y43UgObcgakAC%2FZx4je%2BCoNX5vhkFvgbdQ%3D&reserved=0 > > +$schema: > > https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevicetree.org%2Fmeta-schemas%2Fcore.yaml%23&data=05%7C01%7Colivier.masse%40nxp.com%7C0a9e67bbd65446aa05e408da76f9b82a%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637953112157450452%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=UVuVI%2FmUFj7jX7c6DY0rRi9lkZW7kqTJyQurQxvNvz8%3D&reserved=0 > > + > > +title: Linaro Secure DMABUF Heap > > + > > +maintainers: > > + - Olivier Masse <olivier.masse@xxxxxxx> > > + > > +description: > > + Linaro OP-TEE firmware needs a reserved memory for the > > + Secure Data Path feature (aka SDP). > > + The purpose is to provide a secure memory heap which allow > > + non-secure OS to allocate/free secure buffers. > > + The TEE is reponsible for protecting the SDP memory buffers. > > + TEE Trusted Application can access secure memory references > > + provided as parameters (DMABUF file descriptor). > > + > > +allOf: > > + - $ref: "reserved-memory.yaml" > > + > > +properties: > > + compatible: > > + const: linaro,secure-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 > > + > > +required: > > + - compatible > > + - reg > > + - no-map > > + > > +examples: > > + - | > > + reserved-memory { > > + #address-cells = <2>; > > + #size-cells = <2>; > > + > > + sdp@3e800000 { > > + compatible = "linaro,secure-heap"; > > + no-map; > > + reg = <0 0x3E800000 0 0x00400000>; > > + }; > > + }; > > -- > > 2.25.0 > >