Re: [PATCH v3 3/4] dt-bindings: reserved-memory: Make DMA-BUF CMA heap DT-configurable
From: Rob Herring <robh@kernel.org>
Date: 2021-01-14 14:02:43
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On Tue, Jan 12, 2021 at 05:21:42PM -0800, Minchan Kim wrote:
From: Hyesoo Yu <redacted> Document devicetree binding for chunk cma heap on dma heap framework. The DMA chunk heap supports the bulk allocation of higher order pages.
Why do we need this? What does this do that CMA doesn't? With a CMA area I can believe a carve out is a common, OS independent thing. This looks too closely tied to some Linux thing to go into DT.
Signed-off-by: Hyesoo Yu <redacted> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Hridya Valsaraju <redacted> Change-Id: I8fb231e5a8360e2d8f65947e155b12aa664dde01
Drop this.
quoted hunk ↗ jump to hunk
--- .../reserved-memory/dma_heap_chunk.yaml | 58 +++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 Documentation/devicetree/bindings/reserved-memory/dma_heap_chunk.yamldiff --git a/Documentation/devicetree/bindings/reserved-memory/dma_heap_chunk.yaml b/Documentation/devicetree/bindings/reserved-memory/dma_heap_chunk.yaml new file mode 100644 index 000000000000..3e7fed5fb006 --- /dev/null +++ b/Documentation/devicetree/bindings/reserved-memory/dma_heap_chunk.yaml@@ -0,0 +1,58 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/reserved-memory/dma_heap_chunk.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Device tree binding for chunk heap on DMA HEAP FRAMEWORK + +description: | + The DMA chunk heap is backed by the Contiguous Memory Allocator (CMA) and + supports bulk allocation of fixed size pages. + +maintainers: + - Hyesoo Yu <hyesoo.yu@samsung.com> + - John Stultz <john.stultz@linaro.org> + - Minchan Kim <minchan@kernel.org> + - Hridya Valsaraju<hridya@google.com>
space ^
+ + +properties: + compatible: + enum: + - dma_heap,chunk
The format is <vendor>,<something> and 'dma_heap' is not a vendor.
+
+ chunk-order:
+ description: |
+ order of pages that will get allocated from the chunk DMA heap.
+ maxItems: 1
+
+ size:
+ maxItems: 1
+
+ alignment:
+ maxItems: 1
+
+required:
+ - compatible
+ - size
+ - alignment
+ - chunk-order
+
+additionalProperties: false
+
+examples:
+ - |
+ reserved-memory {
+ #address-cells = <2>;
+ #size-cells = <1>;
+
+ chunk_memory: chunk_memory {
+ compatible = "dma_heap,chunk";
+ size = <0x3000000>;
+ alignment = <0x0 0x00010000>;
+ chunk-order = <4>;
+ };
+ };
+
+
--
2.30.0.284.gd98b1dd5eaa7-goog