Re: [PATCH 1/6] rapidio: add common mapping APIs for RapidIO memory access

[Kumar Gala]

On Jun 11, 2009, at 4:47 AM, Li Yang-R58472 wrote:

> > On May 12, 2009, at 3:35 AM, Li Yang wrote:
> >
> > > Add the mapping functions used to support direct IO memory access of
> > > rapidIO.
> > >
> > > Signed-off-by: Zhang Wei <zw@xxxxxxxxxxxxx>
> > > Signed-off-by: Li Yang <leoli@xxxxxxxxxxxxx>
> >
> > Use inbnd/outbnd instead of inb/outb which make one think of
> > byte level io accessors.
> >
> > As I look at this I don't think this is the correct API.  I
> > think we should be using the DMA mapping API to hide these
> > details.  The concept of mapping like this seems to be more a
> > function of FSL's Address translation/mapping unit (ATMU) than
> > anything specific to the RIO bus standard.
>
> This is a separate RIO block level ATMU.  Although it looks like the
> system level ATMU, system ATMU doesn't have the knowledge of rapidIO
> target device ID.  The mapping need to be dynamic, as it's easy to  
> have
> more RIO devices than the outbound windows.

I understand that.  What I'm saying is the RIO block level ATMU is a  
Freescale specific detail and not part of any standard RIO bus  
programming model.  We have mapping APIs that we can connect to for  
this via the DMA API layer.

- k
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