[PATCH v5 0/6] add generic boot option for IOMMU dma mode

[Zhen Lei]

v4 --> v5:
As Hanjun and Thomas Gleixner's suggestion:
1. Keep the old ARCH specific boot options no change.
2. Keep build option CONFIG_IOMMU_DEFAULT_PASSTHROUGH no change.

v4:
As Robin Murphy's suggestion:
"It's also not necessarily obvious to the user how this interacts with
IOMMU_DEFAULT_PASSTHROUGH, so if we really do go down this route, maybe it
would be better to refactor the whole lot into a single selection of something
like IOMMU_DEFAULT_MODE anyway."

In this version, I tried to normalize the IOMMU dma mode boot options for all
ARCHs. When IOMMU is enabled, there are 3 dma modes: paasthrough(bypass),
lazy(mapping but defer the IOTLB invalidation), strict. But currently each
ARCHs defined their private boot options, different with each other. For
example, to enable/disable "passthrough", ARM64 use iommu.passthrough=1/0,
X86 use iommu=pt/nopt, PPC/POWERNV use iommu=nobypass.

Zhen Lei (6):
  iommu: add generic boot option iommu.dma_mode
  iommu: add build options corresponding to iommu.dma_mode
  iommu: add iommu_default_dma_mode_get/set() helper
  s390/pci: add support for generic boot option iommu.dma_mode
  powernv/iommu: add support for generic boot option iommu.dma_mode
  x86/iommu: add support for generic boot option iommu.dma_mode

 Documentation/admin-guide/kernel-parameters.txt | 19 +++++++
 arch/ia64/include/asm/iommu.h                   |  2 -
 arch/ia64/kernel/pci-dma.c                      |  2 -
 arch/powerpc/platforms/powernv/pci-ioda.c       |  5 +-
 arch/s390/pci/pci_dma.c                         | 14 ++---
 arch/x86/include/asm/iommu.h                    |  1 -
 arch/x86/kernel/pci-dma.c                       | 35 ++++++------
 drivers/iommu/Kconfig                           | 45 ++++++++++++---
 drivers/iommu/amd_iommu.c                       | 10 ++--
 drivers/iommu/amd_iommu_init.c                  |  4 +-
 drivers/iommu/amd_iommu_types.h                 |  6 --
 drivers/iommu/intel-iommu.c                     |  9 ++-
 drivers/iommu/iommu.c                           | 73 ++++++++++++++++++++-----
 include/linux/iommu.h                           | 23 ++++++++
 14 files changed, 176 insertions(+), 72 deletions(-)

-- 
1.8.3