[PATCH v3 0/5] Clean up VMD DMA Map Ops

[Jon Derrick <jonathan.derrick@intel.com>]

v2 Set: https://lore.kernel.org/linux-iommu/1578580256-3483-1-git-send-email-jonathan.derrick@intel.com/T/#t
v1 Set: https://lore.kernel.org/linux-iommu/20200107134125.GD30750@8bytes.org/T/#t

VMD currently works with VT-d enabled by pointing DMA and IOMMU actions at the
VMD endpoint. The problem with this approach is that the VMD endpoint's
device-specific attributes, such as the DMA Mask Bits, are used instead.

This set cleans up VMD by removing the override that redirects DMA map
operations to the VMD endpoint. Instead it introduces a new DMA alias mechanism
into the existing DMA alias infrastructure.

v1 added a pointer in struct pci_dev that pointed to the DMA alias' struct
pci_dev and did the necessary DMA alias and IOMMU modifications.

v2 introduced a new weak function to reference the 'Direct DMA Alias', and
removed the need to add a pointer in struct device or pci_dev. Weak functions
are generally frowned upon when it's a single architecture implementation, so I
am open to alternatives.

v3 references the pci_dev rather than the struct device for the PCI
'Direct DMA Alias' (pci_direct_dma_alias()). This revision also allows
pci_for_each_dma_alias() to call any DMA aliases for the Direct DMA alias
device, though I don't expect the VMD endpoint to need intra-bus DMA aliases.

Changes from v2:
Uses struct pci_dev for PCI Device 'Direct DMA aliasing' (pci_direct_dma_alias)
Allows pci_for_each_dma_alias to iterate over the alias mask of the 'Direct DMA alias'

Changes from v1:
Removed 1/5 & 2/5 misc fix patches that were merged
Uses Christoph's staging/cleanup patches
Introduce weak function rather than including pointer in struct device or pci_dev.

Based on Joerg's next:
https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git/

Jon Derrick (5):
  x86/pci: Add a to_pci_sysdata helper
  x86/PCI: Expose VMD's PCI Device in pci_sysdata
  PCI: Introduce pci_direct_dma_alias()
  PCI: vmd: Stop overriding dma_map_ops
  x86/pci: Remove X86_DEV_DMA_OPS

 arch/x86/Kconfig               |   3 -
 arch/x86/include/asm/device.h  |  10 ---
 arch/x86/include/asm/pci.h     |  31 ++++-----
 arch/x86/pci/common.c          |  45 ++----------
 drivers/iommu/intel-iommu.c    |  18 +++--
 drivers/pci/controller/Kconfig |   1 -
 drivers/pci/controller/vmd.c   | 152 +----------------------------------------
 drivers/pci/pci.c              |  19 +++++-
 drivers/pci/search.c           |   7 ++
 include/linux/pci.h            |   1 +
 10 files changed, 61 insertions(+), 226 deletions(-)

-- 
1.8.3.1