I think all the feedback on these has been addressed, so I'm asking once more if these UIO additions can be considered for inclusion. Thanks, - Chris On Thu, Feb 1, 2024 at 3:34 PM Chris Leech <cleech@xxxxxxxxxx> wrote: > > During bnx2i iSCSI testing we ran into page refcounting issues in the > uio mmaps exported from cnic to the iscsiuio process, and bisected back > to the removal of the __GFP_COMP flag from dma_alloc_coherent calls. > > The cnic uio interface also has issues running with an iommu enabled, > which these changes correct. > > In order to fix these drivers to be able to mmap dma coherent memory via > a uio device, introduce a new uio mmap type backed by dma_mmap_coherent. > > While I understand some complaints about how these drivers have been > structured, I also don't like letting support bitrot when there's a > reasonable alternative to re-architecting an existing driver. I believe > this to be the most sane way to restore these drivers to functioning > properly. > > There are two other uio drivers which are mmaping dma_alloc_coherent > memory as UIO_MEM_PHYS, uio_dmem_genirq and uio_pruss. > These drivers are converted in the later patches of this series. > > v5: > - convert uio_pruss and uio_dmem_genirq > - added dev_warn and comment about not adding more users > - put some PAGE_ALIGNs back in cnic to keep checks in > uio_mmap_dma_coherent matched with uio_mmap_physical. > - dropped the Fixes trailer > v4: > - re-introduce the dma_device member to uio_map, > it needs to be passed to dma_mmap_coherent somehow > - drop patch 3 to focus only on the uio interface, > explicit page alignment isn't needed > - re-add the v1 mail recipients, > this isn't something to be handled through linux-scsi > v3 (Nilesh Javali <njavali@xxxxxxxxxxx>): > - fix warnings reported by kernel test robot > and added base commit > v2 (Nilesh Javali <njavali@xxxxxxxxxxx>): > - expose only the dma_addr within uio and cnic. > - Cleanup newly added unions comprising virtual_addr > and struct device > > previous threads: > v1: https://lore.kernel.org/all/20230929170023.1020032-1-cleech@xxxxxxxxxx/ > attempt at an alternative change: https://lore.kernel.org/all/20231219055514.12324-1-njavali@xxxxxxxxxxx/ > v2: https://lore.kernel.org/all/20240103091137.27142-1-njavali@xxxxxxxxxxx/ > v3: https://lore.kernel.org/all/20240109121458.26475-1-njavali@xxxxxxxxxxx/ > v4: https://lore.kernel.org/all/20240131191732.3247996-1-cleech@xxxxxxxxxx/ > > Chris Leech (4): > uio: introduce UIO_MEM_DMA_COHERENT type > cnic,bnx2,bnx2x: use UIO_MEM_DMA_COHERENT > uio_pruss: UIO_MEM_DMA_COHERENT conversion > uio_dmem_genirq: UIO_MEM_DMA_COHERENT conversion > > drivers/net/ethernet/broadcom/bnx2.c | 1 + > .../net/ethernet/broadcom/bnx2x/bnx2x_main.c | 2 + > drivers/net/ethernet/broadcom/cnic.c | 25 ++++++---- > drivers/net/ethernet/broadcom/cnic.h | 1 + > drivers/net/ethernet/broadcom/cnic_if.h | 1 + > drivers/uio/uio.c | 47 +++++++++++++++++++ > drivers/uio/uio_dmem_genirq.c | 22 ++++----- > drivers/uio/uio_pruss.c | 6 ++- > include/linux/uio_driver.h | 8 ++++ > 9 files changed, 89 insertions(+), 24 deletions(-) > > > base-commit: 861c0981648f5b64c86fd028ee622096eb7af05a > -- > 2.43.0 >
