Re: [PATCH] arm64/dma-mapping: Add DMA_ATTR_ALLOC_SINGLE_PAGES support

From: Yong Wu
Date: Fri Mar 04 2016 - 03:01:57 EST


On Thu, 2016-03-03 at 09:44 -0800, Doug Anderson wrote:
> Hi,
>
> On Wed, Mar 2, 2016 at 10:54 AM, Yong Wu <yong.wu@xxxxxxxxxxxx> wrote:
> > Sometimes it is not worth for the iommu allocating big chunks.
> > Here we enable DMA_ATTR_ALLOC_SINGLE_PAGES which could help avoid to
> > allocate big chunks while iommu allocating buffer.
> >
> > More information about this attribute, please check Doug's commit[1].
> >
> > [1]: https://lkml.org/lkml/2016/1/11/720
> >
> > Cc: Robin Murphy <robin.murphy@xxxxxxx>
> > Suggested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> > ---
> >
> > Our video drivers may soon use this.
> >
> > arch/arm64/mm/dma-mapping.c | 4 ++--
> > drivers/iommu/dma-iommu.c | 14 ++++++++++----
> > include/linux/dma-iommu.h | 4 ++--
> > 3 files changed, 14 insertions(+), 8 deletions(-)
>
> It should also be mentioned that this depends on commit df05c6f6e0bb
> ("ARM: 8506/1: common: DMA-mapping: add DMA_ATTR_ALLOC_SINGLE_PAGES
> attribute") which is not in mainline quite yet.

Thanks. I will add it in the commit message.

>
> Also please CC Marek Szyprowski on any future patches in this area
> since I saw a patch series from him that was touching this same area.

Will do.

>
> Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

Thanks.