Pull iommu updates from Joerg Roedel:

 - Allow compiling the ARM-SMMU drivers as modules.

 - Fixes and cleanups for the ARM-SMMU drivers and io-pgtable code
   collected by Will Deacon. The merge-commit (6855d1ba) has all the
   details.

 - Cleanup of the iommu_put_resv_regions() call-backs in various
   drivers.

 - AMD IOMMU driver cleanups.

 - Update for the x2APIC support in the AMD IOMMU driver.

 - Preparation patches for Intel VT-d nested mode support.

 - RMRR and identity domain handling fixes for the Intel VT-d driver.

 - More small fixes and cleanups.

* tag 'iommu-updates-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (87 commits)
  iommu/amd: Remove the unnecessary assignment
  iommu/vt-d: Remove unnecessary WARN_ON_ONCE()
  iommu/vt-d: Unnecessary to handle default identity domain
  iommu/vt-d: Allow devices with RMRRs to use identity domain
  iommu/vt-d: Add RMRR base and end addresses sanity check
  iommu/vt-d: Mark firmware tainted if RMRR fails sanity check
  iommu/amd: Remove unused struct member
  iommu/amd: Replace two consecutive readl calls with one readq
  iommu/vt-d: Don't reject Host Bridge due to scope mismatch
  PCI/ATS: Add PASID stubs
  iommu/arm-smmu-v3: Return -EBUSY when trying to re-add a device
  iommu/arm-smmu-v3: Improve add_device() error handling
  iommu/arm-smmu-v3: Use WRITE_ONCE() when changing validity of an STE
  iommu/arm-smmu-v3: Add second level of context descriptor table
  iommu/arm-smmu-v3: Prepare for handling arm_smmu_write_ctx_desc() failure
  iommu/arm-smmu-v3: Propagate ssid_bits
  iommu/arm-smmu-v3: Add support for Substream IDs
  iommu/arm-smmu-v3: Add context descriptor tables allocators
  iommu/arm-smmu-v3: Prepare arm_smmu_s1_cfg for SSID support
  ACPI/IORT: Parse SSID property of named component node
  ...