[v3,00/21] .map_sg() error cleanup

Hi,

This v3 of the series is spun out and expanded from my work to add
P2PDMA support to DMA map operations[1]. v2 is at [2]. The main changes
in v1 are to more carefully define the meaning of the error codes for
dma_map_sgtable().

The P2PDMA work requires distinguishing different error conditions in
a map_sg operation. dma_map_sgtable() already allows for returning an
error code (where as dma_map_sg() is only allowed to return zero)
however, it currently only returns -EINVAL when a .map_sg() call returns
zero.

This series cleans up all .map_sg() implementations to return appropriate
error codes. After the cleanup, dma_map_sg() will still return zero,
however dma_map_sgtable() will pass the error code from the .map_sg()
call. Thanks go to Martn Oliveira for doing a lot of the cleanup of the
obscure implementations.

The patch set is based off of v5.14-rc2 and a git repo can be found
here:

  https://github.com/sbates130272/linux-p2pmem map_sg_err_cleanup_v2

Thanks,

Logan

[1] https://lore.kernel.org/linux-block/20210513223203.5542-1-logang@deltatee.com/
[2] https://lore.kernel.org/linux-mips/20210723175008.22410-1-logang@deltatee.com/

--

Changes in v3:
  - Move the validation of errnos into __dma_map_sg_attrs() (Per
    Christoph)
  - Fix the out of date commit message in patch 21 (Per Eike)
Changes in v2:
  - Attempt to define the meanings of the errors returned by
    dma_map_sgtable() and restrict the valid return codes of
    .map_sg implementations. (Per Christoph)
  - Change dma_map_sgtable() to EXPORT_SYMBOL_GPL() (Per Christoph)
  - Add patches to remove the erroneous setting of sg->dma_address
    to DMA_MAP_ERROR in a few .map_sg(0 implementations. (Per
    Christoph).

--

Logan Gunthorpe (10):
  dma-mapping: Allow map_sg() ops to return negative error codes
  dma-direct: Return appropriate error code from dma_direct_map_sg()
  iommu: Return full error code from iommu_map_sg[_atomic]()
  dma-iommu: Return error code from iommu_dma_map_sg()
  ARM/dma-mapping: don't set failed sg dma_address to DMA_MAPPING_ERROR
  powerpc/iommu: don't set failed sg dma_address to DMA_MAPPING_ERROR
  s390/pci: don't set failed sg dma_address to DMA_MAPPING_ERROR
  sparc/iommu: don't set failed sg dma_address to DMA_MAPPING_ERROR
  x86/amd_gart: don't set failed sg dma_address to DMA_MAPPING_ERROR
  dma-mapping: Disallow .map_sg operations from returning zero on error

Martin Oliveira (11):
  alpha: return error code from alpha_pci_map_sg()
  ARM/dma-mapping: return error code from .map_sg() ops
  ia64/sba_iommu: return error code from sba_map_sg_attrs()
  MIPS/jazzdma: return error code from jazz_dma_map_sg()
  powerpc/iommu: return error code from .map_sg() ops
  s390/pci: return error code from s390_dma_map_sg()
  sparc/iommu: return error codes from .map_sg() ops
  parisc: return error code from .map_sg() ops
  xen: swiotlb: return error code from xen_swiotlb_map_sg()
  x86/amd_gart: return error code from gart_map_sg()
  dma-mapping: return error code from dma_dummy_map_sg()

 arch/alpha/kernel/pci_iommu.c           | 10 ++-
 arch/arm/mm/dma-mapping.c               | 26 +++++---
 arch/ia64/hp/common/sba_iommu.c         |  6 +-
 arch/mips/jazz/jazzdma.c                |  2 +-
 arch/powerpc/kernel/iommu.c             |  6 +-
 arch/powerpc/platforms/ps3/system-bus.c |  2 +-
 arch/powerpc/platforms/pseries/vio.c    |  5 +-
 arch/s390/pci/pci_dma.c                 | 13 ++--
 arch/sparc/kernel/iommu.c               |  6 +-
 arch/sparc/kernel/pci_sun4v.c           |  6 +-
 arch/sparc/mm/iommu.c                   |  2 +-
 arch/x86/kernel/amd_gart_64.c           | 18 +++---
 drivers/iommu/dma-iommu.c               | 23 ++++---
 drivers/iommu/iommu.c                   | 15 +++--
 drivers/parisc/ccio-dma.c               |  2 +-
 drivers/parisc/sba_iommu.c              |  2 +-
 drivers/xen/swiotlb-xen.c               |  2 +-
 include/linux/dma-map-ops.h             |  5 +-
 include/linux/dma-mapping.h             | 35 +++--------
 include/linux/iommu.h                   | 22 +++----
 kernel/dma/direct.c                     |  2 +-
 kernel/dma/dummy.c                      |  2 +-
 kernel/dma/mapping.c                    | 82 ++++++++++++++++++++++---
 23 files changed, 177 insertions(+), 117 deletions(-)


base-commit: ff1176468d368232b684f75e82563369208bc371
--
2.20.1

Thanks,

I've applied this to the dma-mapping tree with a few minor cosmetic
tweaks.