Bring in this file from Linux v6.5 Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx> --- Changes in v4: - New patch .../reserved-memory/reserved-memory.yaml | 181 ++++++++++++++++++ 1 file changed, 181 insertions(+) create mode 100644 dtschema/schemas/reserved-memory/reserved-memory.yaml diff --git a/dtschema/schemas/reserved-memory/reserved-memory.yaml b/dtschema/schemas/reserved-memory/reserved-memory.yaml new file mode 100644 index 0000000..c680e39 --- /dev/null +++ b/dtschema/schemas/reserved-memory/reserved-memory.yaml @@ -0,0 +1,181 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/reserved-memory/reserved-memory.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: /reserved-memory Child Node Common + +maintainers: + - devicetree-spec@xxxxxxxxxxxxxxx + +description: > + Reserved memory is specified as a node under the /reserved-memory node. The + operating system shall exclude reserved memory from normal usage one can + create child nodes describing particular reserved (excluded from normal use) + memory regions. Such memory regions are usually designed for the special + usage by various device drivers. + + Each child of the reserved-memory node specifies one or more regions + of reserved memory. Each child node may either use a 'reg' property to + specify a specific range of reserved memory, or a 'size' property with + optional constraints to request a dynamically allocated block of + memory. + + Following the generic-names recommended practice, node names should + reflect the purpose of the node (ie. "framebuffer" or "dma-pool"). + Unit address (@<address>) should be appended to the name if the node + is a static allocation. + +properties: + reg: true + + size: + oneOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - $ref: /schemas/types.yaml#/definitions/uint64 + description: > + Length based on parent's \#size-cells. Size in bytes of memory to + reserve. + + alignment: + oneOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - $ref: /schemas/types.yaml#/definitions/uint64 + description: > + Length based on parent's \#size-cells. Address boundary for + alignment of allocation. + + alloc-ranges: + $ref: /schemas/types.yaml#/definitions/uint32-array + description: > + Address and Length pairs. Specifies regions of memory that are + acceptable to allocate from. + + iommu-addresses: + $ref: /schemas/types.yaml#/definitions/phandle-array + description: > + A list of phandle and specifier pairs that describe static IO virtual + address space mappings and carveouts associated with a given reserved + memory region. The phandle in the first cell refers to the device for + which the mapping or carveout is to be created. + + The specifier consists of an address/size pair and denotes the IO + virtual address range of the region for the given device. The exact + format depends on the values of the "#address-cells" and "#size-cells" + properties of the device referenced via the phandle. + + When used in combination with a "reg" property, an IOVA mapping is to + be established for this memory region. One example where this can be + useful is to create an identity mapping for physical memory that the + firmware has configured some hardware to access (such as a bootsplash + framebuffer). + + If no "reg" property is specified, the "iommu-addresses" property + defines carveout regions in the IOVA space for the given device. This + can be useful if a certain memory region should not be mapped through + the IOMMU. + + no-map: + type: boolean + description: > + Indicates the operating system must not create a virtual mapping + of the region as part of its standard mapping of system memory, + nor permit speculative access to it under any circumstances other + than under the control of the device driver using the region. + + reusable: + type: boolean + description: > + The operating system can use the memory in this region with the + limitation that the device driver(s) owning the region need to be + able to reclaim it back. Typically that means that the operating + system can use that region to store volatile or cached data that + can be otherwise regenerated or migrated elsewhere. + +allOf: + - if: + required: + - no-map + + then: + not: + required: + - reusable + + - if: + required: + - reusable + + then: + not: + required: + - no-map + +oneOf: + - oneOf: + - required: + - reg + + - required: + - size + + - oneOf: + # IOMMU reservations + - required: + - iommu-addresses + + # IOMMU mappings + - required: + - reg + - iommu-addresses + +additionalProperties: true + +examples: + - | + / { + compatible = "foo"; + model = "foo"; + + #address-cells = <2>; + #size-cells = <2>; + + reserved-memory { + #address-cells = <2>; + #size-cells = <2>; + ranges; + + adsp_resv: reservation-adsp { + /* + * Restrict IOVA mappings for ADSP buffers to the 512 MiB region + * from 0x40000000 - 0x5fffffff. Anything outside is reserved by + * the ADSP for I/O memory and private memory allocations. + */ + iommu-addresses = <&adsp 0x0 0x00000000 0x00 0x40000000>, + <&adsp 0x0 0x60000000 0xff 0xa0000000>; + }; + + fb: framebuffer@90000000 { + reg = <0x0 0x90000000 0x0 0x00800000>; + iommu-addresses = <&dc0 0x0 0x90000000 0x0 0x00800000>; + }; + }; + + bus@0 { + #address-cells = <1>; + #size-cells = <1>; + ranges = <0x0 0x0 0x0 0x40000000>; + + adsp: adsp@2990000 { + reg = <0x2990000 0x2000>; + memory-region = <&adsp_resv>; + }; + + dc0: display@15200000 { + reg = <0x15200000 0x10000>; + memory-region = <&fb>; + }; + }; + }; +... -- 2.42.0.rc2.253.gd59a3bf2b4-goog
