Messages in this thread | | | Date | Mon, 21 Nov 2016 00:08:30 -0500 | From | Jerome Glisse <> | Subject | Re: [HMM v13 07/18] mm/ZONE_DEVICE/x86: add support for un-addressable device memory |
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On Mon, Nov 21, 2016 at 01:08:56PM +1100, Balbir Singh wrote: > > > On 19/11/16 05:18, Jérôme Glisse wrote: > > It does not need much, just skip populating kernel linear mapping > > for range of un-addressable device memory (it is pick so that there > > is no physical memory resource overlapping it). All the logic is in > > share mm code. > > > > Only support x86-64 as this feature doesn't make much sense with > > constrained virtual address space of 32bits architecture. > > > > Is there a reason this would not work on powerpc64 for example? > Could you document the limitations -- testing/APIs/missing features?
It should be straight forward for powerpc64, i haven't done it but i certainly can try to get access to some powerpc64 and add support for it.
The only thing to do is to avoid creating kernel linear mapping for the un-addressable memory (just for safety reasons we do not want any read/ write to invalid physical address).
Cheers, Jérôme
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