Re: [PATCH v7 06/07] iommu/ipmmu-vmsa: ARM and ARM64 archdata access

From	Magnus Damm <magnus.damm@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v7 06/07] iommu/ipmmu-vmsa: ARM and ARM64 archdata access
Date	2017-03-09 04:50 +0100
Message-ID	<tiXfr-7KJ-5@gated-at.bofh.it> (permalink)
References	<tie8G-1nN-7@gated-at.bofh.it> <tie8G-1nN-13@gated-at.bofh.it> <tiJct-6C3-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

Hi Robin,

On Wed, Mar 8, 2017 at 9:48 PM, Robin Murphy <robin.murphy@arm.com> wrote:
> On 07/03/17 03:17, Magnus Damm wrote:
>> From: Magnus Damm <damm+renesas@opensource.se>
>>
>> Not all architectures have an iommu member in their archdata, so
>> use #ifdefs support build with COMPILE_TEST on any architecture.
>
> I have a feeling I might be repeating myself, but ipmmu_vmsa_archdata
> looks to be trivially convertible to iommu_fwspec, which I strongly
> encourage, not least because it would obviate bodges like this.

Yeah, I think it should be possible to use iommu_fwspec for this
purpose. The question is when to do it. =)

I actually looked into it recently, but then realised that for this to
work then due to code sharing I need to make use of iommu_fwspec on
both 32-bit and 64-bit ARM. So it requires rework of the existing
IPMMU for 32-bit ARM (including hairy legacy CONFIG_IOMMU_DMA=n code).
I was actually thinking of doing some rework of 32-bit ARM IPMMU code
anyway (I suspect iommu_device_* conversion caused breakage) and it
probably has to happen on top of current -next. I would also like to
start reducing burden of forward porting all these patches, and
stirring up the ground does not really help much there...

Cheers,

/ magnus

Thread

[PATCH v7 06/07] iommu/ipmmu-vmsa: ARM and ARM64 archdata access Magnus Damm <magnus.damm@gmail.com> - 2017-03-07 04:40 +0100
  Re: [PATCH v7 06/07] iommu/ipmmu-vmsa: ARM and ARM64 archdata access Geert Uytterhoeven <geert@linux-m68k.org> - 2017-03-08 11:00 +0100
  Re: [PATCH v7 06/07] iommu/ipmmu-vmsa: ARM and ARM64 archdata access Robin Murphy <robin.murphy@arm.com> - 2017-03-08 13:50 +0100
    Re: [PATCH v7 06/07] iommu/ipmmu-vmsa: ARM and ARM64 archdata access Magnus Damm <magnus.damm@gmail.com> - 2017-03-09 04:50 +0100
      Re: [PATCH v7 06/07] iommu/ipmmu-vmsa: ARM and ARM64 archdata access Robin Murphy <robin.murphy@arm.com> - 2017-03-09 12:50 +0100

csiph-web