Hi Ilyes,
>But still, you guys need assistance from the kernel-space to
>resolve the phys. addresses related to those malloc'ed buffers
>(which aren't necessarily contiguous in phys. RAM), so that to
>populate the GPU MMU, right?
Yes.
>Is it the case? If yes, is this done in gfxdriver or the
>system driver (via a dedicated surface pool)?
Neither. As I tried to note previously, there are underlying
graphics drivers (that exist in both user and kernel mode which
are not part of DFB) that are used/called by the DFB graphics
drivers. For example:
App
|
DFB core
|
DFB graphics driver
|
Custom graphics driver
such as an OGL ES driver
with custom extensions
|
User |
=====================================
Kernel |
|
Custom graphics driver KO
There is no dedicated surface pool for system memory surfaces.
Cheers,
Timothy
>-----Original Message-----
>From: Ilyes Gouta [mailto:[email protected]]
>Sent: Friday, July 01, 2011 2:01 PM
>To: Strelchun, Timothy
>Cc: [email protected]
>Subject: Re: [directfb-dev] [PATCH] GPU system memory support
>mods for aligned buffer directfbrc commands (was RE: [PATCH] 3
>patch set...)
>
>Hi Timothy,
>
>> It is not shared with the CPU MMU and is instead part of the
>GPU unit
>> on our different SOCs. We do not provide replacements for DFB's
>> memory allocation functions. The underlying graphics
>drivers used by
>> our DFB graphics drivers handle setting up the needed GPU
>MMU mappings for the malloc'd memory pages (which are locked
>and cannot move) and hide that complexity from the DFB layer.
>
>But still, you guys need assistance from the kernel-space to
>resolve the phys. addresses related to those malloc'ed buffers
>(which aren't necessarily contiguous in phys. RAM), so that to
>populate the GPU MMU, right?
>
>Is it the case? If yes, is this done in gfxdriver or the
>system driver (via a dedicated surface pool)?
>
>Thanks for bearing with me!
>
>-Ilyes
>
>>
>> Cheers,
>> Timothy
>>
>>>-----Original Message-----
>>>From: Ilyes Gouta [mailto:[email protected]]
>>>Sent: Wednesday, June 22, 2011 1:19 AM
>>>To: Strelchun, Timothy
>>>Cc: [email protected]
>>>Subject: Re: [directfb-dev] [PATCH] GPU system memory
>support mods for
>>>aligned buffer directfbrc commands (was RE: [PATCH] 3 patch set...)
>>>
>>>Hi Timothy,
>>>
>>>Out of curiosity, is that blitter MMU kind of "shared" with
>the CPU's
>>>MMU? or do you guys provide your own replacements for
>>>malloc()/realloc()/free(), for DirectFB?
>>>
>>>Thanks,
>>>
>>>-Ilyes
>>>
>>>On Tue, Jun 21, 2011 at 11:31 PM, Strelchun, Timothy
>>><[email protected]> wrote:
>>>> Hi Ilyes,
>>>>
>>>>>Is your h/w blitter able to cope with the virtual
>addresses (as seen
>>>>>within the user-space process) of the DirectFB surfaces?
>>>>
>>>> Yes, that is correct. Any graphics driver that reports
>>>support for system memory surfaces would need to have a way to deal
>>>with the non-physically contiguous (virtual) memory associated with
>>>them (such as via their own MMU that's setup by the driver).
>>>>
>>>> Cheers,
>>>> Timothy
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