> -----Original Message-----
> From: Laura Abbott [mailto:labb...@redhat.com]
> Sent: Monday, October 08, 2018 21:26
> To: Skidanov, Alexey <alexey.skida...@intel.com>;
> de...@driverdev.osuosl.org
> Cc: Sumit Semwal <sumit.sem...@linaro.org>
> Subject: Re: staging: android: ion: aligned allocation support
>
> On 10/03/2018 01:03 PM, Alexey Skidanov wrote:
> >
> >
> > On 10/03/2018 09:07 PM, Laura Abbott wrote:
> >> On 10/02/2018 07:27 AM, Alexey Skidanov wrote:
> >>> Hi,
> >>>
> >>> Sometimes HW requires memory buffer to be aligned in order to be used
> >>> properly. Of course, we may overcome the lack of aligned allocation
> >>> support, but we may easily add it because CMA and gen_pool (used by
> >>> several heaps) already support it.
> >>>
> >>> Does someone have an objection to add it?
> >>>
> >>> Thanks,
> >>> Alexey
> >>>
> >>
> >> The alignment option was removed from the allocation API before
> >> because the most common heap (system heap) didn't support it
> >> and it was causing more confusion. We've already mangled the
> >> ABI once so I really don't want to break it again. I'm not
> >> opposed to adding alignment support for the CMA via the allocation
> >> flags.
> > Currently, the flags member is used to define the way the buffer will be
> > mapped - cached or uncached. So,if I understand you correct, we need to
> > add ION_FLAG_ALIGNED flag and to share 32 bit field between flags and
> > flags specific data (alignment value) ?
> >
>
> Yes, that's what I was thinking.
Excellent. I will prepare the patch.
>
> > I'm probably going to remove the carveout and chunk heap because
> >> nobody has stepped up to figure out how to tie allocation of those
> >> to device tree or another method.
> >>
> >> Thanks,
> >> Laura
> >
> > Thanks,
> > Alexey
> >
Thanks,
Alexey
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