Merge tag 'iommu-updates-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:

 - Debugfs support for the Intel VT-d driver.

   When enabled, it now also exposes some of its internal data
   structures to user-space for debugging purposes.

 - ARM-SMMU driver now uses the generic deferred flushing and fast-path
   iova allocation code.

   This is expected to be a major performance improvement, as this
   allocation path scales a lot better.

 - Support for r8a7744 in the Renesas iommu driver

 - Couple of minor fixes and improvements all over the place

* tag 'iommu-updates-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (39 commits)
  iommu/arm-smmu-v3: Remove unnecessary wrapper function
  iommu/arm-smmu-v3: Add SPDX header
  iommu/amd: Add default branch in amd_iommu_capable()
  dt-bindings: iommu: ipmmu-vmsa: Add r8a7744 support
  iommu/amd: Move iommu_init_pci() to .init section
  iommu/arm-smmu: Support non-strict mode
  iommu/io-pgtable-arm-v7s: Add support for non-strict mode
  iommu/arm-smmu-v3: Add support for non-strict mode
  iommu/io-pgtable-arm: Add support for non-strict mode
  iommu: Add "iommu.strict" command line option
  iommu/dma: Add support for non-strict mode
  iommu/arm-smmu: Ensure that page-table updates are visible before TLBI
  iommu/arm-smmu-v3: Implement flush_iotlb_all hook
  iommu/arm-smmu-v3: Avoid back-to-back CMD_SYNC operations
  iommu/arm-smmu-v3: Fix unexpected CMD_SYNC timeout
  iommu/io-pgtable-arm: Fix race handling in split_blk_unmap()
  iommu/arm-smmu-v3: Fix a couple of minor comment typos
  iommu: Fix a typo
  iommu: Remove .domain_{get,set}_windows
  iommu: Tidy up window attributes
  ...

1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 8022d902e770..5b5f1ba76bba 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1759,6 +1759,18 @@
 		nobypass	[PPC/POWERNV]
 			Disable IOMMU bypass, using IOMMU for PCI devices.
 
+	iommu.strict=	[ARM64] Configure TLB invalidation behaviour
+			Format: { "0" | "1" }
+			0 - Lazy mode.
+			  Request that DMA unmap operations use deferred
+			  invalidation of hardware TLBs, for increased
+			  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).
+			  DMA unmap operations invalidate IOMMU hardware TLBs
+			  synchronously.
+
 	iommu.passthrough=
 			[ARM64] Configure DMA to bypass the IOMMU by default.
 			Format: { "0" | "1" }