Some parts of the memory can be dedicated to specific purposes and exposed as a dedicated memory allocator.
This is especially useful if that particular region has a particular properties the rest of the memory doesn't have. For example, some platforms have their entire RAM covered by ECC but for a small area meant to be used by applications that don't need ECC, and its associated overhead.
Let's introduce a binding to describe such a region and allow the OS to create a dedicated memory allocator for it.
Signed-off-by: Maxime Ripard mripard@kernel.org --- .../bindings/reserved-memory/carved-out.yaml | 49 ++++++++++++++++++++++ 1 file changed, 49 insertions(+)
diff --git a/Documentation/devicetree/bindings/reserved-memory/carved-out.yaml b/Documentation/devicetree/bindings/reserved-memory/carved-out.yaml new file mode 100644 index 0000000000000000000000000000000000000000..9ab5d1ebd9ebd9111b7c064fabe1c45e752da83b --- /dev/null +++ b/Documentation/devicetree/bindings/reserved-memory/carved-out.yaml @@ -0,0 +1,49 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/reserved-memory/carved-out.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Carved-out Memory Region + +description: | + Specifies that the reserved memory region has been carved out of the + main memory allocator, and is intended to be used by the OS as a + dedicated memory allocator. + +maintainers: + - Maxime Ripard mripard@kernel.org + +properties: + compatible: + const: carved-out + + reg: + description: region of memory that is carved out. + +allOf: + - $ref: reserved-memory.yaml + - not: + required: + - reusable + - not: + required: + - no-map + +required: + - compatible + - reg + +unevaluatedProperties: false + +examples: + - | + reserved-memory { + #address-cells = <1>; + #size-cells = <1>; + + memory@12340000 { + compatible = "carved-out"; + reg = <0x12340000 0x00800000>; + }; + };