[PATCH v2 7/9] dpaa_eth: fix iova handling for contiguous frames

[Christoph Hellwig]

On Sat, Apr 27, 2019 at 10:10:29AM +0300, laurentiu.tudor at nxp.com wrote:
> From: Laurentiu Tudor <laurentiu.tudor at nxp.com>
> 
> The driver relies on the no longer valid assumption that dma addresses
> (iovas) are identical to physical addressees and uses phys_to_virt() to
> make iova -> vaddr conversions. Fix this by adding a function that does
> proper iova -> phys conversions using the iommu api and update the code
> to use it.
> Also, a dma_unmap_single() call had to be moved further down the code
> because iova -> vaddr conversions were required before the unmap.
> For now only the contiguous frame case is handled and the SG case is
> split in a following patch.
> While at it, clean-up a redundant dpaa_bpid2pool() and pass the bp
> as parameter.

Err, this is broken.  A driver using the DMA API has no business
call IOMMU APIs.  Just save the _virtual_ address used for the mapping
away and use that again.  We should not go through crazy gymnastics
like this.