[PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource

Niklas Söderlund niso at kth.se
Mon Apr 25 07:26:19 PDT 2016

Hi Christoph,

On 2016-04-21 06:49:42 -0700, Christoph Hellwig wrote:
> On Wed, Apr 13, 2016 at 03:29:17PM +0200, Niklas S?derlund wrote:
> > > Yes, it would be good to do an audit of all the ARM dma_ops as well
> > > as generic code like drivers/base/dma-*.c, lib/dma-debug.c and
> > > include/linux/dma-*.h
> What about things like the phys_addr() helper in lib/dma-debug.c?  That
> was in fact what prompted my question for an audit, and it seems
> to not even feature on your list.  What patterns / symbols did you look
> for?

I have followed the call path from the usage in 
drivers/dma/sh/rcar-dmac.c and made sure the dma_addr_t is not used in a 
bad way.

I also looked at the dma-mapping API and ruled out that the only 
function that make sens to use with a dma_addr_t from dma_map_resource() 
are dma_unmap_resource() and dma_mapping_error(). With that I can't see 
how a dma_addr_t would end up in lib/dma-debug.c. But I might be missing 

In the big picture do you feel the approach I have is the correct way to 
solve my problem? Provided we can work out this issues ofc?

Niklas Söderlund

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