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@xxxxxxxxxxxxx/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@xxxxxxxxxxxxx>
Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Acked-by: Rob Herring <robh@xxxxxxxxxx>
Acked-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
Acked-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Patch 2/3 and 3/3 are quite trivial but have no acked-by so far.
Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
---
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(-)
