Messages in this thread | | | Subject | Re: [v4,0/3] iommu/ipmmu-vmsa: r8a7796 support V4 | From | Oleksandr <> | Date | Tue, 5 Sep 2017 19:52:29 +0300 |
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Hi, Magnus, maintainers, all.
On 19.06.17 14:04, Magnus Damm wrote: > iommu/ipmmu-vmsa: r8a7796 support V4 > > [PATCH v4 1/3] iommu/ipmmu-vmsa: Add r8a7796 DT binding > [PATCH v4 2/3] iommu/ipmmu-vmsa: Increase maximum micro-TLBS to 48 > [PATCH v4 3/3] iommu/ipmmu-vmsa: Hook up r8a7796 DT matching code > > This series adds r8a7796 support to the IPMMU driver. The DT binding > gets updated, maximum number of micro-TLBs are increased and the > driver is adjusted to match on the new DT binding. I am interested in adding IPMMU-VMSA support to Xen hypervisor.
I did some preparations for making IPMMU-VMSA to feel comfortable [1] inside Xen followed by direct porting Linux IPMMU-VMSA driver and ARM LPAE page-table allocator [2] to it.
I decided to base on the "BSP" driver [3] because it had more complete support than the "mainline" one [4].
During review I got a feedback that "BSP" driver wasn't the best choice to be ported. Xen ARM maintainers worry about "BSP" driver which haven't had a thorough review by the Linux community and as the result might have bugs which will never be fixed, etc.
So, for the IPMMU-VMSA support to be accepted by Xen community I should either write our own driver based on BSP/mainline/whatever which contains only relevant to Xen things or direct port from "mainline" driver. As the second option relies on the required support [5] which isn't in mainline yet, it is not clear when this support gets merged and how it will be modified/reworked before, we preliminarily decided to follow the first option. But, I would like to consider second option again. Despite the complexity of second option, it has one significant benefit.
I see that Linux driver is being developed quite actively and looking over all related patch series I got a feeling that required support was about to reach upstream.
Could you, please, clarify some questions which, I hope, help us to make a decision: 1. Do you have approximate time-frame for getting this support in? 2. Are fundamental/significant changes planned for this support?
Also, may I ask for a link to github branch which contains current (and likely r8a7795 and 32-bit ARM update) patch series?
Thank you in advance!
And sorry for the most likely incorrect format of this email.
[1] https://www.mail-archive.com/xen-devel@lists.xen.org/msg115901.html [2] https://lists.xen.org/archives/html/xen-devel/2017-07/msg02679.html [3] https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas-bsp.git/tree/drivers/iommu/ipmmu-vmsa.c?h=v4.9/rcar-3.5.3 [4] http://elixir.free-electrons.com/linux/latest/source/drivers/iommu/ipmmu-vmsa.c [5] https://lists.linuxfoundation.org/pipermail/iommu/2017-June/022567.html https://lists.linuxfoundation.org/pipermail/iommu/2017-June/022577.html https://lkml.org/lkml/2017/7/17/393 > > Changes since V3: > - Rebased on top of [PATCH v4 00/09] iommu/ipmmu-vmsa: r8a7795 support V4 > - Patch 3/3 updated with Reviewed-by - thanks Geert! > > Changes since V2: > - Patch 2/3 updated with an outer set of () - thanks Ramesh! > - Patch 2/3 updated with Reviewed-by - thanks Geert! > - Patch 3/3 updated to include white list support > > Changes since V1: > - Patch 1/3 updated with more Acked-by tags > - Patch 2/3 updated with high I/O register range support > > Patch 1/3 is ready for upstream merge and includes the following tags: > Signed-off-by: Magnus Damm <damm+renesas@opensource.se> > Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > Acked-by: Rob Herring <robh@kernel.org> > Acked-by: Simon Horman <horms+renesas@verge.net.au> > Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> > > Patch 2/3 and 3/3 are quite trivial but have no acked-by so far. > > Signed-off-by: Magnus Damm <damm+renesas@opensource.se> > --- > > Developed on top of next-20170614 with the following series applied > [PATCH 00/04] iommu/ipmmu-vmsa: 32-bit ARM update > [PATCH v4 00/09] iommu/ipmmu-vmsa: r8a7795 support V4 > > Documentation/devicetree/bindings/iommu/renesas,ipmmu-vmsa.txt | 1 > drivers/iommu/ipmmu-vmsa.c | 24 +++++++--- > 2 files changed, 18 insertions(+), 7 deletions(-)
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