diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-iommu_groups | 30 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/iommu/arm,smmu.yaml | 9 |
3 files changed, 37 insertions, 7 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-iommu_groups b/Documentation/ABI/testing/sysfs-kernel-iommu_groups index 017f5bc3920c..0fedbb0f94e4 100644 --- a/Documentation/ABI/testing/sysfs-kernel-iommu_groups +++ b/Documentation/ABI/testing/sysfs-kernel-iommu_groups @@ -33,3 +33,33 @@ Description: In case an RMRR is used only by graphics or USB devices it is now exposed as "direct-relaxable" instead of "direct". In device assignment use case, for instance, those RMRR are considered to be relaxable and safe. + +What: /sys/kernel/iommu_groups/<grp_id>/type +Date: November 2020 +KernelVersion: v5.11 +Contact: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> +Description: /sys/kernel/iommu_groups/<grp_id>/type shows the type of default + domain in use by iommu for this group. See include/linux/iommu.h + for possible read values. A privileged user could request kernel to + change the group type by writing to this file. Valid write values: + + ======== ====================================================== + DMA All the DMA transactions from the device in this group + are translated by the iommu. + identity All the DMA transactions from the device in this group + are not translated by the iommu. + auto Change to the type the device was booted with. + ======== ====================================================== + + The default domain type of a group may be modified only when + + - The group has only one device. + - The device in the group is not bound to any device driver. + So, the users must unbind the appropriate driver before + changing the default domain type. + + Unbinding a device driver will take away the driver's control + over the device and if done on devices that host root file + system could lead to catastrophic effects (the users might + need to reboot the machine to get it to normal state). So, it's + expected that the users understand what they're doing. diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index c0ca130fe3c9..a28982dfee6e 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1883,11 +1883,6 @@ Note that using this option lowers the security provided by tboot because it makes the system vulnerable to DMA attacks. - nobounce [Default off] - Disable bounce buffer for untrusted devices such as - the Thunderbolt devices. This will treat the untrusted - devices as the trusted ones, hence might expose security - risks of DMA attacks. intel_idle.max_cstate= [KNL,HW,ACPI,X86] 0 disables intel_idle and fall back on acpi_idle. diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml index 503160a7b9a0..3b63f2ae24db 100644 --- a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml @@ -28,8 +28,6 @@ properties: - enum: - qcom,msm8996-smmu-v2 - qcom,msm8998-smmu-v2 - - qcom,sc7180-smmu-v2 - - qcom,sdm845-smmu-v2 - const: qcom,smmu-v2 - description: Qcom SoCs implementing "arm,mmu-500" @@ -40,6 +38,13 @@ properties: - qcom,sm8150-smmu-500 - qcom,sm8250-smmu-500 - const: arm,mmu-500 + - description: Qcom Adreno GPUs implementing "arm,smmu-v2" + items: + - enum: + - qcom,sc7180-smmu-v2 + - qcom,sdm845-smmu-v2 + - const: qcom,adreno-smmu + - const: qcom,smmu-v2 - description: Marvell SoCs implementing "arm,mmu-500" items: - const: marvell,ap806-smmu-500 |