Re: [PATCHv9 0/6] dmaengine: rcar-dmac: add iommu support for slave transfers

[Vinod Koul <vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

On Wed, Aug 10, 2016 at 01:22:13PM +0200, Niklas Söderlund wrote:
> Hi,
> 
> This series tries to solve the problem with DMA with device registers
> (MMIO registers) that are behind an IOMMU for the rcar-dmac driver. A
> recent patch '9575632 (dmaengine: make slave address physical)'
> clarifies that DMA slave address provided by clients is the physical
> address. This puts the task of mapping the DMA slave address from a
> phys_addr_t to a dma_addr_t on the DMA engine.
> 
> Without an IOMMU this is easy since the phys_addr_t and dma_addr_t are
> the same and no special care is needed. However if you have a IOMMU you
> need to map the DMA slave phys_addr_t to a dma_addr_t using something
> like this.
> 
> This series is based on top of v4.8-rc1. And I'm hoping to be able to collect a
> Ack from Russell King on patch 4/6 that adds the ARM specific part and then be
> able to take the whole series through the dmaengine tree. If this is not the
> best route I'm more then happy to do it another way.
> 
> It's tested on a Koelsch with CONFIG_IPMMU_VMSA and by enabling the
> ipmmu_ds node in r8a7791.dtsi. I verified operation by interacting with
> /dev/mmcblk1, i2c and the serial console which are devices behind the
> iommu.

As I said in last one, the dmaengine parts look fine to me. But to go thru
dmaengine tree I would need ACK on non dmaengine patches.


-- 
~Vinod