linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Lee Jones <lee.jones@linaro.org>
Cc: Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	iommu@lists.linux-foundation.org,
	open list <linux-kernel@vger.kernel.org>,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>,
	Patrick Daly <pdaly@codeaurora.org>,
	Pratik Patel <pratikp@codeaurora.org>,
	Rob Clark <robdclark@gmail.com>,
	Thierry Reding <treding@nvidia.com>
Subject: Re: [PATCH 0/3] iommu/arm-smmu: Qualcomm bootsplash/efifb
Date: Mon, 24 May 2021 22:28:10 -0500	[thread overview]
Message-ID: <YKxuynamQBTrNksO@yoga> (raw)
In-Reply-To: <CAF2Aj3iKk2LSA5XC76pNiLV8a76BkibUitof-dix8rqkc0qiow@mail.gmail.com>

On Mon 24 May 07:03 CDT 2021, Lee Jones wrote:

> On Wed, 8 Jan 2020 at 09:16, Will Deacon <will@kernel.org> wrote:
> 
> > On Thu, Dec 26, 2019 at 02:17:06PM -0800, Bjorn Andersson wrote:
> > > These patches implements the stream mapping inheritance that's necessary
> > in
> > > order to not hit a security violation as the display hardware looses its
> > stream
> > > mapping during initialization of arm-smmu in various Qualcomm platforms.
> > >
> > > This was previously posted as an RFC [1], changes since then involves the
> > > rebase and migration of the read-back code to the Qualcomm specific
> > > implementation, the mapping is maintained indefinitely - to handle probe
> > > deferring clients - and rewritten commit messages.
> >
> > I don't think we should solve this in a Qualcomm-specific manner. Please
> > can
> > you take a look at the proposal from Thierry [1] and see whether or not it
> > works for you?
> >
> 
> Did this or Thierry's solution ever gain traction?
> 

There was a few pieces that landed in the common code which allowed us
to deal with the quirks of the Qualcomm platform (turned out that just
reading back the settings wasn't the only piece necessary).

The "generic" solution is essentially the second half of
qcom_smmu_cfg_probe(), which ensures that as the SMMU is reset it will
do so with bypass mappings for all stream mappings the boot loader left
us.

> Or are all the parties still 'solving' this downstream?
> 

I believe that Qualcomm has adopted the upstream solution in their
downstream kernel.

Regards,
Bjorn

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

      parent reply	other threads:[~2021-05-25  3:56 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-26 22:17 [PATCH 0/3] iommu/arm-smmu: Qualcomm bootsplash/efifb Bjorn Andersson
2019-12-26 22:17 ` [PATCH 1/3] iommu/arm-smmu: Don't blindly use first SMR to calculate mask Bjorn Andersson
2019-12-26 22:17 ` [PATCH 2/3] iommu/arm-smmu: Expose s2cr and smr structs to impl Bjorn Andersson
2019-12-26 22:17 ` [PATCH 3/3] iommu/arm-smmu: Allow inherting stream mapping from bootloader Bjorn Andersson
2020-01-08  9:16 ` [PATCH 0/3] iommu/arm-smmu: Qualcomm bootsplash/efifb Will Deacon
     [not found]   ` <CAF2Aj3iKk2LSA5XC76pNiLV8a76BkibUitof-dix8rqkc0qiow@mail.gmail.com>
2021-05-24 12:48     ` Robin Murphy
2021-05-25  3:28     ` Bjorn Andersson [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YKxuynamQBTrNksO@yoga \
    --to=bjorn.andersson@linaro.org \
    --cc=iommu@lists.linux-foundation.org \
    --cc=joro@8bytes.org \
    --cc=lee.jones@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pdaly@codeaurora.org \
    --cc=pratikp@codeaurora.org \
    --cc=robdclark@gmail.com \
    --cc=robin.murphy@arm.com \
    --cc=treding@nvidia.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).