[PATCH 1/6] rapidio: add common mapping APIs for RapidIO memory access
Kumar Gala
galak at kernel.crashing.org
Thu Jun 11 23:32:24 EST 2009
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 at zh-kernel.org>
>>> Signed-off-by: Li Yang <leoli at freescale.com>
>>
>> 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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