Re: [PATCH 0/5] iommu: Some IOVA code reorganisation

From: Robin Murphy
Date: Tue Nov 16 2021 - 09:26:03 EST

On 2021-11-16 14:21, John Garry wrote:
On 04/10/2021 12:44, Will Deacon wrote:
On Fri, Sep 24, 2021 at 06:01:52PM +0800, John Garry wrote:
The IOVA domain structure is a bit overloaded, holding:
- IOVA tree management
- FQ control
- IOVA rcache memories

Indeed only a couple of IOVA users use the rcache, and only dma-iommu.c
uses the FQ feature.

This series separates out that structure. In addition, it moves the FQ
code into dma-iommu.c . This is not strictly necessary, but it does make
it easier for the FQ domain lookup the rcache domain.

The rcache code stays where it is, as it may be reworked in future, so
there is not much point in relocating and then discarding.

This topic was initially discussed and suggested (I think) by Robin here:
It would be useful to have Robin's Ack on patches 2-4. The implementation
looks straightforward to me, but the thread above isn't very clear about
what is being suggested.

Hi Robin,

Just wondering if you had made any progress on your FQ code rework or your own re-org?

Hey John - as it happens I started hacking on that in earnest about half an hour ago, aiming to get something out later this week.


I wasn't planning on progressing until this is done first (and that is still a big issue), even though not strictly necessary.