Re: [PATCH 1/2] drivers: dma-coherent: Add support for default DMA coherent pool

[Rob Herring]

On Mon, Jul 03, 2017 at 05:51:14PM +0300, vitaly_kuzmichev@xxxxxxxxxx wrote:
> From: "George G. Davis" <george_davis@xxxxxxxxxx>
> 
> Use concept similar to the default CMA region for DMA coherent pools.

Why do we need this in DT? CMA is a carveout and has to be reserved 
early, but DMA coherent memory is just different MMU attributes, right?

Also, does this still apply with DMA mapping changes in 4.13?

> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: George G. Davis <george_davis@xxxxxxxxxx>
> Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
> Signed-off-by: Mark Craske <Mark_Craske@xxxxxxxxxx>
> Signed-off-by: Vitaly Kuzmichev <Vitaly_Kuzmichev@xxxxxxxxxx>
> ---
>  .../bindings/reserved-memory/reserved-memory.txt   |  2 ++
>  drivers/base/dma-coherent.c                        | 29 ++++++++++++++++------
>  2 files changed, 24 insertions(+), 7 deletions(-)