Re: [Xen-devel] [PATCH RFC 13/18] xen: introduce and use 'dom0_rambase_pfn' setting for kernel Dom0

[Oleksandr Dmytryshyn <oleksandr.dmytryshyn@xxxxxxxxxxxxxxx>]

On Fri, May 20, 2016 at 7:05 PM, Edgar E. Iglesias
<edgar.iglesias@xxxxxxxxx> wrote:
> Hi,
>
> We have similar needs (not exactly the same) in some of our setups.
> We need to map certain OCMs (On Chip Memories) to dom0. Among other things,
> these are used to communicate with remote accelerators/CPUs that have
> "hardcoded" addresses to these RAMs.
>
> Our approach is more along the lines of Juliens second suggestion. We're
> trying to use the mmio-sram DTS bindings to bring in these memories into
> dom0.
>
> IIUC the Ducati FW issue correctly, you need to allocate a chunk of DDR.
>
> Another possible solution:
> I think you could reserve the memory area by simply not mentioning it
> in the main memory node (these nodes support multiple ranges so you can
> introduce gaps). Then you could for example create an mmio-sram node to
> get the memory explicitely mapped 1:1 into dom0.
>
> Just a moment ago, I posted an RFC for the mmio-sram support to the list.
Hi, Edgar.

How do You access to the mapped OCMs in dom0?
Are genalloc-related functions (gen_pool_get/_alloc/_virt_to_phys)
only way to work with mmio-sram memory?

> Cheers,
> Edgar
>
>
>>
>> Regards,
>>
>> [1]
>> http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg01879.html
>> [2]
>> http://lists.xenproject.org/archives/html/xen-devel/2016-05/msg01894.html
>>
>> --
>> Julien Grall
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxx
>> http://lists.xen.org/xen-devel

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