Re: [PATCH v2] lib/scatterlist: Provide a DMA page iterator

[Thomas Hellstrom]

On Thu, 2019-02-07 at 22:26 +0000, Jason Gunthorpe wrote:
> Commit 2db76d7c3c6d ("lib/scatterlist: sg_page_iter: support sg lists
> w/o
> backing pages") introduced the sg_page_iter_dma_address() function
> without
> providing a way to use it in the general case. If the sg_dma_len() is
> not
> equal to the sg length callers cannot safely use the
> for_each_sg_page/sg_page_iter_dma_address combination.
> 
> Resolve this API mistake by providing a DMA specific iterator,
> for_each_sg_dma_page(), that uses the right length so
> sg_page_iter_dma_address() works as expected with all sglists.
> 
> A new iterator type is introduced to provide compile-time safety
> against
> wrongly mixing accessors and iterators.
> 
> Acked-by: Christoph Hellwig <hch@xxxxxx> (for scatterlist)
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> 

For the vmwgfx part, 
Acked-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>

I'll take a deeper look to provide a vmwgfx fix as a follow up.

Thanks,
Thomas