[PATCH v11 0/3] Enhance IOMMU default DMA mode build options

[John Garry]

This is a reboot of Zhen Lei's series from a couple of years ago, which
never made it across the line.

I still think that it has some value, so taking up the mantle.

Motivation:
Allow lazy mode be default mode for DMA domains for all ARCHs, and not
only those who hardcode it (to be lazy). For ARM64, currently we must use
a kernel command line parameter to use lazy mode, which is less than
ideal.

Differences to v10:
- Rebase to v5.13-rc4
- Correct comment and typo in Kconfig (Randy)
- Make Kconfig choice depend on relevant architectures

Differences to v9:
https://lore.kernel.org/linux-iommu/20190613084240.16768-1-thunder.leizhen@xxxxxxxxxx/#t
- Rebase to v5.13-rc2
- Remove CONFIG_IOMMU_DEFAULT_PASSTHROUGH from choice:
  Since we can dynamically change default domain of group, lazy or strict and
  passthrough are not mutually exclusive
- Drop ia64 patch, which I don't think was ever required
- Drop "x86/dma: use IS_ENABLED() to simplify the code", which is no
  longer required
- Drop s390/pci patch, as this arch does not use CONFIG_IOMMU_API or even
  already honour CONFIG_IOMMU_DEFAULT_PASSTHROUGH
  https://lore.kernel.org/linux-iommu/20190613084240.16768-4-thunder.leizhen@xxxxxxxxxx/
- Drop powernv/iommu patch, as I no longer think that it is relevant
  https://lore.kernel.org/linux-iommu/20190613084240.16768-5-thunder.leizhen@xxxxxxxxxx/
- Some tidying

Zhen Lei (3):
  iommu: Enhance IOMMU default DMA mode build options
  iommu/vt-d: Add support for IOMMU default DMA mode build options
  iommu/amd: Add support for IOMMU default DMA mode build options

 drivers/iommu/Kconfig       | 36 ++++++++++++++++++++++++++++++++++++
 drivers/iommu/amd/init.c    |  3 ++-
 drivers/iommu/intel/iommu.c |  2 +-
 drivers/iommu/iommu.c       |  3 ++-
 4 files changed, 41 insertions(+), 3 deletions(-)

-- 
2.26.2