> -----Original Message----- > From: Laura Abbott [mailto:labbott@xxxxxxxxxx] > Sent: Monday, October 08, 2018 21:26 > To: Skidanov, Alexey <alexey.skidanov@xxxxxxxxx>; > devel@xxxxxxxxxxxxxxxxxxxx > Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx> > 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 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
