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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-03 08:22:13 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-03 08:22:13 +0300 |
commit | dcd68326d29b62f3039e4f4d23d3e38f24d37360 (patch) | |
tree | b02e363257d2362dc29b251ae2e23efaf598cb07 /Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml | |
parent | 624ad333d49e136c54a342ce0009a05b439616be (diff) | |
parent | 4c7a7d5086cd0f9ce22bb3df86604576d0604db5 (diff) | |
download | linux-dcd68326d29b62f3039e4f4d23d3e38f24d37360.tar.xz |
Merge tag 'devicetree-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring:
- Convert /reserved-memory bindings to schemas
- Convert a bunch of NFC bindings to schemas
- Convert bindings to schema: Xilinx USB, Freescale DDR controller, Arm
CCI-400, UBlox Neo-6M, 1-Wire GPIO, MSI controller, ASpeed LPC, OMAP
and Inside-Secure HWRNG, register-bit-led, OV5640, Silead GSL1680,
Elan ekth3000, Marvell bluetooth, TI wlcore, TI bluetooth, ESP
ESP8089, tlm,trusted-foundations, Microchip cap11xx, Ralink SoCs and
boards, and TI sysc
- New binding schemas for: msi-ranges, Aspeed UART routing controller,
palmbus, Xylon LogiCVC display controller, Mediatek's MT7621 SDRAM
memory controller, and Apple M1 PCIe host
- Run schema checks for %.dtb targets
- Improve build time when using DT_SCHEMA_FILES
- Improve error message when dtschema is not found
- Various doc reference fixes in MAINTAINERS
- Convert architectures to common CPU h/w ID parsing function
of_get_cpu_hwid().
- Allow for empty NUMA node IDs which may be hotplugged
- Cleanup of __fdt_scan_reserved_mem()
- Constify device_node parameters
- Update dtc to upstream v1.6.1-19-g0a3a9d3449c8. Adds new checks
'node_name_vs_property_name' and 'interrupt_map'.
- Enable dtc 'unit_address_format' warning by default
- Fix unittest EXPECT text for gpio hog errors
* tag 'devicetree-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (97 commits)
dt-bindings: net: ti,bluetooth: Document default max-speed
dt-bindings: pci: rcar-pci-ep: Document r8a7795
dt-bindings: net: qcom,ipa: IPA does support up to two iommus
of/fdt: Remove of_scan_flat_dt() usage for __fdt_scan_reserved_mem()
of: unittest: document intentional interrupt-map provider build warning
of: unittest: fix EXPECT text for gpio hog errors
of/unittest: Disable new dtc node_name_vs_property_name and interrupt_map warnings
scripts/dtc: Update to upstream version v1.6.1-19-g0a3a9d3449c8
dt-bindings: arm: firmware: tlm,trusted-foundations: Convert txt bindings to yaml
dt-bindings: display: tilcd: Fix endpoint addressing in example
dt-bindings: input: microchip,cap11xx: Convert txt bindings to yaml
dt-bindings: ufs: exynos-ufs: add exynosautov9 compatible
dt-bindings: ufs: exynos-ufs: add io-coherency property
dt-bindings: mips: convert Ralink SoCs and boards to schema
dt-bindings: display: xilinx: Fix example with psgtr
dt-bindings: net: nfc: nxp,pn544: Convert txt bindings to yaml
dt-bindings: Add a help message when dtschema tools are missing
dt-bindings: bus: ti-sysc: Update to use yaml binding
dt-bindings: sram: Allow numbers in sram region node name
dt-bindings: display: Document the Xylon LogiCVC display controller
...
Diffstat (limited to 'Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml')
-rw-r--r-- | Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml b/Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml new file mode 100644 index 000000000000..a4bf757d6881 --- /dev/null +++ b/Documentation/devicetree/bindings/reserved-memory/shared-dma-pool.yaml @@ -0,0 +1,87 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/reserved-memory/shared-dma-pool.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: /reserved-memory DMA pool node bindings + +maintainers: + - devicetree-spec@vger.kernel.org + +allOf: + - $ref: "reserved-memory.yaml" + +properties: + compatible: + oneOf: + - const: shared-dma-pool + description: > + This indicates a region of memory meant to be used as a shared + pool of DMA buffers for a set of devices. It can be used by an + operating system to instantiate the necessary pool management + subsystem if necessary. + + - const: restricted-dma-pool + description: > + This indicates a region of memory meant to be used as a pool + of restricted DMA buffers for a set of devices. The memory + region would be the only region accessible to those devices. + When using this, the no-map and reusable properties must not + be set, so the operating system can create a virtual mapping + that will be used for synchronization. The main purpose for + restricted DMA is to mitigate the lack of DMA access control + on systems without an IOMMU, which could result in the DMA + accessing the system memory at unexpected times and/or + unexpected addresses, possibly leading to data leakage or + corruption. The feature on its own provides a basic level of + protection against the DMA overwriting buffer contents at + unexpected times. However, to protect against general data + leakage and system memory corruption, the system needs to + provide way to lock down the memory access, e.g., MPU. Note + that since coherent allocation needs remapping, one must set + up another device coherent pool by shared-dma-pool and use + dma_alloc_from_dev_coherent instead for atomic coherent + allocation. + + linux,cma-default: + type: boolean + description: > + If this property is present, then Linux will use the region for + the default pool of the contiguous memory allocator. + + linux,dma-default: + type: boolean + description: > + If this property is present, then Linux will use the region for + the default pool of the consistent DMA allocator. + +unevaluatedProperties: false + +examples: + - | + reserved-memory { + #address-cells = <1>; + #size-cells = <1>; + ranges; + + /* global autoconfigured region for contiguous allocations */ + linux,cma { + compatible = "shared-dma-pool"; + reusable; + size = <0x4000000>; + alignment = <0x2000>; + linux,cma-default; + }; + + display_reserved: framebuffer@78000000 { + reg = <0x78000000 0x800000>; + }; + + restricted_dma_reserved: restricted-dma-pool@50000000 { + compatible = "restricted-dma-pool"; + reg = <0x50000000 0x4000000>; + }; + }; + +... |