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
  ...

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.