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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-17 00:58:47 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-17 00:58:47 +0300 |
commit | 19778dd504b5ff5c3c1283aa3da7a56f34c2c3b0 (patch) | |
tree | 6e673f8b95663a7c56726984859ac3cf191df5c0 /Documentation/ABI/testing | |
parent | 007c74e16c1aac9f5c93b372a054f7f11ede8628 (diff) | |
parent | 5ae9a046a452d60b6a6c076f6df7e3f8e34f918f (diff) | |
download | linux-19778dd504b5ff5c3c1283aa3da7a56f34c2c3b0.tar.xz |
Merge tag 'iommu-updates-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull IOMMU updates from Will Deacon:
"There's a good mixture of improvements to the core code and driver
changes across the board.
One thing worth pointing out is that this includes a quirk to work
around behaviour in the i915 driver (see 65f746e8285f ("iommu: Add
quirk for Intel graphic devices in map_sg")), which otherwise
interacts badly with the conversion of the intel IOMMU driver over to
the DMA-IOMMU APU but has being fixed properly in the DRM tree.
We'll revert the quirk later this cycle once we've confirmed that
things don't fall apart without it.
Summary:
- IOVA allocation optimisations and removal of unused code
- Introduction of DOMAIN_ATTR_IO_PGTABLE_CFG for parameterising the
page-table of an IOMMU domain
- Support for changing the default domain type in sysfs
- Optimisation to the way in which identity-mapped regions are
created
- Driver updates:
* Arm SMMU updates, including continued work on Shared Virtual
Memory
* Tegra SMMU updates, including support for PCI devices
* Intel VT-D updates, including conversion to the IOMMU-DMA API
- Cleanup, kerneldoc and minor refactoring"
* tag 'iommu-updates-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (50 commits)
iommu/amd: Add sanity check for interrupt remapping table length macros
dma-iommu: remove __iommu_dma_mmap
iommu/io-pgtable: Remove tlb_flush_leaf
iommu: Stop exporting free_iova_mem()
iommu: Stop exporting alloc_iova_mem()
iommu: Delete split_and_remove_iova()
iommu/io-pgtable-arm: Remove unused 'level' parameter from iopte_type() macro
iommu: Defer the early return in arm_(v7s/lpae)_map
iommu: Improve the performance for direct_mapping
iommu: avoid taking iova_rbtree_lock twice
iommu/vt-d: Avoid GFP_ATOMIC where it is not needed
iommu/vt-d: Remove set but not used variable
iommu: return error code when it can't get group
iommu: Fix htmldocs warnings in sysfs-kernel-iommu_groups
iommu: arm-smmu-impl: Add a space before open parenthesis
iommu: arm-smmu-impl: Use table to list QCOM implementations
iommu/arm-smmu: Move non-strict mode to use io_pgtable_domain_attr
iommu/arm-smmu: Add support for pagetable config domain attribute
iommu: Document usage of "/sys/kernel/iommu_groups/<grp_id>/type" file
iommu: Take lock before reading iommu group default domain type
...
Diffstat (limited to 'Documentation/ABI/testing')
-rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-iommu_groups | 30 |
1 files changed, 30 insertions, 0 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. |