lkml.org 
[lkml]   [2017]   [Sep]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [v4,0/3] iommu/ipmmu-vmsa: r8a7796 support V4
From
Date

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(-)

\
 
 \ /
  Last update: 2017-09-05 18:53    [W:0.055 / U:1.572 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site