diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-iommu_groups | 6 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 29 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/iommu/apple,dart.yaml | 81 |
3 files changed, 98 insertions, 18 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-iommu_groups b/Documentation/ABI/testing/sysfs-kernel-iommu_groups index eae2f1c1e11e..b15af6a5bc08 100644 --- a/Documentation/ABI/testing/sysfs-kernel-iommu_groups +++ b/Documentation/ABI/testing/sysfs-kernel-iommu_groups @@ -42,8 +42,12 @@ Description: /sys/kernel/iommu_groups/<grp_id>/type shows the type of default ======== ====================================================== DMA All the DMA transactions from the device in this group are translated by the iommu. + DMA-FQ As above, but using batched invalidation to lazily + remove translations after use. This may offer reduced + overhead at the cost of reduced memory protection. identity All the DMA transactions from the device in this group - are not translated by the iommu. + are not translated by the iommu. Maximum performance + but zero protection. auto Change to the type the device was booted with. ======== ====================================================== diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index bdb22006f713..87d46cb76121 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -290,10 +290,7 @@ amd_iommu= [HW,X86-64] Pass parameters to the AMD IOMMU driver in the system. Possible values are: - fullflush - enable flushing of IO/TLB entries when - they are unmapped. Otherwise they are - flushed before they will be reused, which - is a lot of faster + fullflush - Deprecated, equivalent to iommu.strict=1 off - do not initialize any AMD IOMMU found in the system force_isolation - Force device isolation for all @@ -1944,18 +1941,17 @@ this case, gfx device will use physical address for DMA. strict [Default Off] - With this option on every unmap_single operation will - result in a hardware IOTLB flush operation as opposed - to batching them for performance. + Deprecated, equivalent to iommu.strict=1. sp_off [Default Off] By default, super page will be supported if Intel IOMMU has the capability. With this option, super page will not be supported. - sm_on [Default Off] - By default, scalable mode will be disabled even if the - hardware advertises that it has support for the scalable - mode translation. With this option set, scalable mode - will be used on hardware which claims to support it. + sm_on + Enable the Intel IOMMU scalable mode if the hardware + advertises that it has support for the scalable mode + translation. + sm_off + Disallow use of the Intel IOMMU scalable mode. tboot_noforce [Default Off] Do not force the Intel IOMMU enabled under tboot. By default, tboot will force Intel IOMMU on, which @@ -2047,13 +2043,12 @@ throughput at the cost of reduced device isolation. Will fall back to strict mode if not supported by the relevant IOMMU driver. - 1 - Strict mode (default). + 1 - Strict mode. DMA unmap operations invalidate IOMMU hardware TLBs synchronously. - Note: on x86, the default behaviour depends on the - equivalent driver-specific parameters, but a strict - mode explicitly specified by either method takes - precedence. + unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}. + Note: on x86, strict mode specified via one of the + legacy driver-specific options takes precedence. iommu.passthrough= [ARM64, X86] Configure DMA to bypass the IOMMU by default. diff --git a/Documentation/devicetree/bindings/iommu/apple,dart.yaml b/Documentation/devicetree/bindings/iommu/apple,dart.yaml new file mode 100644 index 000000000000..94aa9e9afa59 --- /dev/null +++ b/Documentation/devicetree/bindings/iommu/apple,dart.yaml @@ -0,0 +1,81 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/iommu/apple,dart.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Apple DART IOMMU + +maintainers: + - Sven Peter <sven@svenpeter.dev> + +description: |+ + Apple SoCs may contain an implementation of their Device Address + Resolution Table which provides a mandatory layer of address + translations for various masters. + + Each DART instance is capable of handling up to 16 different streams + with individual pagetables and page-level read/write protection flags. + + This DART IOMMU also raises interrupts in response to various + fault conditions. + +properties: + compatible: + const: apple,t8103-dart + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + + clocks: + description: + Reference to the gate clock phandle if required for this IOMMU. + Optional since not all IOMMUs are attached to a clock gate. + + '#iommu-cells': + const: 1 + description: + Has to be one. The single cell describes the stream id emitted by + a master to the IOMMU. + +required: + - compatible + - reg + - '#iommu-cells' + - interrupts + +additionalProperties: false + +examples: + - |+ + dart1: iommu@82f80000 { + compatible = "apple,t8103-dart"; + reg = <0x82f80000 0x4000>; + interrupts = <1 781 4>; + #iommu-cells = <1>; + }; + + master1 { + iommus = <&dart1 0>; + }; + + - |+ + dart2a: iommu@82f00000 { + compatible = "apple,t8103-dart"; + reg = <0x82f00000 0x4000>; + interrupts = <1 781 4>; + #iommu-cells = <1>; + }; + dart2b: iommu@82f80000 { + compatible = "apple,t8103-dart"; + reg = <0x82f80000 0x4000>; + interrupts = <1 781 4>; + #iommu-cells = <1>; + }; + + master2 { + iommus = <&dart2a 0>, <&dart2b 1>; + }; |