[PATCH v2 00/21] .map_sg() error cleanup

From: Logan Gunthorpe (logang@xxxxxxxxxxxx)
Date: Fri Jul 23 2021 - 13:50:33 EST


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

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

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

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



[1] https://lore.kernel.org/linux-block/20210513223203.5542-1-logang@xxxxxxxxxxxx/
[2] https://lore.kernel.org/linux-mips/20210715164544.6827-1-logang@xxxxxxxxxxxx/


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


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 | 86 ++++++++++++++++++++++---
23 files changed, 181 insertions(+), 117 deletions(-)

base-commit: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c