Re: [mm PATCH v3 00/23] Add support for DMA writable pages being writable by the network stack

[Alexander Duyck]

On Thu, Nov 10, 2016 at 3:34 AM, Alexander Duyck
<alexander.h.duyck@xxxxxxxxx> wrote:
> The first 19 patches in the set add support for the DMA attribute
> DMA_ATTR_SKIP_CPU_SYNC on multiple platforms/architectures.  This is needed
> so that we can flag the calls to dma_map/unmap_page so that we do not
> invalidate cache lines that do not currently belong to the device.  Instead
> we have to take care of this in the driver via a call to
> sync_single_range_for_cpu prior to freeing the Rx page.
>
> Patch 20 adds support for dma_map_page_attrs and dma_unmap_page_attrs so
> that we can unmap and map a page using the DMA_ATTR_SKIP_CPU_SYNC
> attribute.
>
> Patch 21 adds support for freeing a page that has multiple references being
> held by a single caller.  This way we can free page fragments that were
> allocated by a given driver.
>
> The last 2 patches use these updates in the igb driver, and lay the
> groundwork to allow for us to reimplement the use of build_skb.
>
> v1: Minor fixes based on issues found by kernel build bot
>     Few minor changes for issues found on code review
>     Added Acked-by for patches that were acked and not changed
>
> v2: Added a few more Acked-by
>     Submitting patches to mm instead of net-next
>
> v3: Added Acked-by for PowerPC architecture
>     Dropped first 3 patches which were accepted into swiotlb tree
>     Dropped comments describing swiotlb changes.
>
> ---
>
> Alexander Duyck (23):
>       arch/arc: Add option to skip sync on DMA mapping
>       arch/arm: Add option to skip sync on DMA map and unmap
>       arch/avr32: Add option to skip sync on DMA map
>       arch/blackfin: Add option to skip sync on DMA map
>       arch/c6x: Add option to skip sync on DMA map and unmap
>       arch/frv: Add option to skip sync on DMA map
>       arch/hexagon: Add option to skip DMA sync as a part of mapping
>       arch/m68k: Add option to skip DMA sync as a part of mapping
>       arch/metag: Add option to skip DMA sync as a part of map and unmap
>       arch/microblaze: Add option to skip DMA sync as a part of map and unmap
>       arch/mips: Add option to skip DMA sync as a part of map and unmap
>       arch/nios2: Add option to skip DMA sync as a part of map and unmap
>       arch/openrisc: Add option to skip DMA sync as a part of mapping
>       arch/parisc: Add option to skip DMA sync as a part of map and unmap
>       arch/powerpc: Add option to skip DMA sync as a part of mapping
>       arch/sh: Add option to skip DMA sync as a part of mapping
>       arch/sparc: Add option to skip DMA sync as a part of map and unmap
>       arch/tile: Add option to skip DMA sync as a part of map and unmap
>       arch/xtensa: Add option to skip DMA sync as a part of mapping
>       dma: Add calls for dma_map_page_attrs and dma_unmap_page_attrs
>       mm: Add support for releasing multiple instances of a page
>       igb: Update driver to make use of DMA_ATTR_SKIP_CPU_SYNC
>       igb: Update code to better handle incrementing page count
>
>
>  arch/arc/mm/dma.c                         |    5 ++
>  arch/arm/common/dmabounce.c               |   16 ++++--
>  arch/avr32/mm/dma-coherent.c              |    7 ++-
>  arch/blackfin/kernel/dma-mapping.c        |    8 +++
>  arch/c6x/kernel/dma.c                     |   14 ++++-
>  arch/frv/mb93090-mb00/pci-dma-nommu.c     |   14 ++++-
>  arch/frv/mb93090-mb00/pci-dma.c           |    9 +++
>  arch/hexagon/kernel/dma.c                 |    6 ++
>  arch/m68k/kernel/dma.c                    |    8 +++
>  arch/metag/kernel/dma.c                   |   16 +++++-
>  arch/microblaze/kernel/dma.c              |   10 +++-
>  arch/mips/loongson64/common/dma-swiotlb.c |    2 -
>  arch/mips/mm/dma-default.c                |    8 ++-
>  arch/nios2/mm/dma-mapping.c               |   26 +++++++---
>  arch/openrisc/kernel/dma.c                |    3 +
>  arch/parisc/kernel/pci-dma.c              |   20 ++++++--
>  arch/powerpc/kernel/dma.c                 |    9 +++
>  arch/sh/kernel/dma-nommu.c                |    7 ++-
>  arch/sparc/kernel/iommu.c                 |    4 +-
>  arch/sparc/kernel/ioport.c                |    4 +-
>  arch/tile/kernel/pci-dma.c                |   12 ++++-
>  arch/xtensa/kernel/pci-dma.c              |    7 ++-
>  drivers/net/ethernet/intel/igb/igb.h      |    7 ++-
>  drivers/net/ethernet/intel/igb/igb_main.c |   77 +++++++++++++++++++----------
>  include/linux/dma-mapping.h               |   20 +++++---
>  include/linux/gfp.h                       |    2 +
>  mm/page_alloc.c                           |   14 +++++
>  27 files changed, 246 insertions(+), 89 deletions(-)
>

So I am just wondering if I need to resubmit this to pick up the new
"Acked-by"s or if I should just wait?

As I said in the description my hope is to get this into the -mm tree
and I am not familiar with what the process is for being accepted
there.

Thanks.

- Alex