diff options
Diffstat (limited to 'Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml')
| -rw-r--r-- | Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml | 89 |
1 files changed, 85 insertions, 4 deletions
diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml index b205215b130d..c680e397cfd2 100644 --- a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml +++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.yaml @@ -52,6 +52,30 @@ properties: 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: > @@ -89,12 +113,69 @@ allOf: - no-map oneOf: - - required: - - reg + - oneOf: + - required: + - reg + + - required: + - size + + - oneOf: + # IOMMU reservations + - required: + - iommu-addresses - - required: - - size + # 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>; + }; + }; + }; ... |