[PATCH v7 00/10] iommu/amd: Use 128-bit cmpxchg operation to update DTE

Suravee Suthikulpanit posted 10 patches 1 day, 10 hours ago
There is a newer version of this series
drivers/iommu/amd/amd_iommu.h       |   4 +-
drivers/iommu/amd/amd_iommu_types.h |  40 ++-
drivers/iommu/amd/init.c            | 224 +++++++++--------
drivers/iommu/amd/iommu.c           | 370 ++++++++++++++++++++--------
include/asm-generic/rwonce.h        |   2 +-
include/linux/compiler_types.h      |   8 +-
6 files changed, 434 insertions(+), 214 deletions(-)
[PATCH v7 00/10] iommu/amd: Use 128-bit cmpxchg operation to update DTE
Posted by Suravee Suthikulpanit 1 day, 10 hours ago
This series modifies current implementation to use 128-bit cmpxchg to
update DTE when needed as specified in the AMD I/O Virtualization
Techonology (IOMMU) Specification.

Please note that I have verified with the hardware designer, and they have
confirmed that the IOMMU hardware has always been implemented with 256-bit
read. The next revision of the IOMMU spec will be updated to correctly
describe this part.  Therefore, I have updated the implementation to avoid
unnecessary flushing.

Changes in v7:

* Patch 1: Newly added

* Patch 4: Newly added
  Replace struct dev_data.initial_dte with global amd_ivhd_dev_flags_list
  to store persistent DTE fields for devices. The previous design has a major
  drawbacks where it needs to allocate the struct dev_data unnecessarily for
  non-existing devices to store initial DTE values.

* Patch 6: Clean up per Jason

* Patch 10: Newly added

v6: https://lore.kernel.org/lkml/20241016051756.4317-1-suravee.suthikulpanit@amd.com/ 
v5: https://lore.kernel.org/lkml/20241007041353.4756-1-suravee.suthikulpanit@amd.com/
v4: https://lore.kernel.org/lkml/20240916171805.324292-1-suravee.suthikulpanit@amd.com/
v3: https://lore.kernel.org/lkml/20240906121308.5013-1-suravee.suthikulpanit@amd.com/
v2: https://lore.kernel.org/lkml/20240829180726.5022-1-suravee.suthikulpanit@amd.com/
v1: https://lore.kernel.org/lkml/20240819161839.4657-1-suravee.suthikulpanit@amd.com/

Thanks,
Suravee

Suravee Suthikulpanit (9):
  iommu/amd: Misc ACPI IVRS debug info clean up
  iommu/amd: Disable AMD IOMMU if CMPXCHG16B feature is not supported
  iommu/amd: Introduce struct ivhd_dte_flags to store persistent DTE
    flags
  iommu/amd: Introduce helper function to update 256-bit DTE
  iommu/amd: Modify set_dte_entry() to use 256-bit DTE helpers
  iommu/amd: Introduce helper function get_dte256()
  iommu/amd: Modify clear_dte_entry() to avoid in-place update
  iommu/amd: Lock DTE before updating the entry with WRITE_ONCE()
  iommu/amd: Remove amd_iommu_apply_erratum_63()

Uros Bizjak (1):
  asm/rwonce: Introduce [READ|WRITE]_ONCE() support for __int128

 drivers/iommu/amd/amd_iommu.h       |   4 +-
 drivers/iommu/amd/amd_iommu_types.h |  40 ++-
 drivers/iommu/amd/init.c            | 224 +++++++++--------
 drivers/iommu/amd/iommu.c           | 370 ++++++++++++++++++++--------
 include/asm-generic/rwonce.h        |   2 +-
 include/linux/compiler_types.h      |   8 +-
 6 files changed, 434 insertions(+), 214 deletions(-)

-- 
2.34.1