From: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
To: Will Deacon <will@kernel.org>
Cc: iommu@lists.linux-foundation.org, robin.murphy@arm.com,
sspatil@android.com
Subject: Re: Users of IOMMU_QCOM_SYS_CACHE?
Date: Thu, 24 Oct 2019 17:01:05 +0530 [thread overview]
Message-ID: <257ea3fb1740ba7b968e1ddfbbb94a52@codeaurora.org> (raw)
In-Reply-To: <20191024112130.GD1242@willie-the-truck>
On 2019-10-24 16:51, Will Deacon wrote:
> On Thu, Oct 24, 2019 at 04:41:04PM +0530, Sai Prakash Ranjan wrote:
>> On 2019-10-24 16:21, Will Deacon wrote:
>> > In commit 90ec7a76cc4b ("iommu/io-pgtable-arm: Add support to use system
>> > cache") we added support for IOMMU_QCOM_SYS_CACHE which was merged into
>> > 5.3.
>> > This allows non-coherent devices to request an outer cacheable memory
>> > type.... except that nobody actually does this in mainline. I remember
>> > there
>> > being a potential DRM user but I don't know what happened to it.
>> >
>> > Given that this isn't actually exposed in the DMA API, I worry that
>> > we're
>> > just carrying part of an out-of-tree hack here and propose that we drop
>> > the flag altogether unless we get an upstream user, preferably by
>> > plumbing
>> > this into the DMA API via a new attribute.
>> >
>> > Thoughts?
>> >
>>
>> There is definitely a user of this coming soon atleast for SC7180 SoC
>> once
>> we have support for this SoC upstream.
>
> Ok, I'm keen to see how you end up using this. How soon is soon?
>
We have already started upstreaming for SC7180, so this should also come
pretty soon. Sorry, I cannot tell the exact date but can make sure that
your message reaches to appropriate team.
Thanks,
Sai
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member
of Code Aurora Forum, hosted by The Linux Foundation
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2019-10-24 11:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-24 10:51 Users of IOMMU_QCOM_SYS_CACHE? Will Deacon
2019-10-24 11:11 ` Sai Prakash Ranjan
2019-10-24 11:21 ` Will Deacon
2019-10-24 11:31 ` Sai Prakash Ranjan [this message]
2019-10-24 15:38 ` Jordan Crouse
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=257ea3fb1740ba7b968e1ddfbbb94a52@codeaurora.org \
--to=saiprakash.ranjan@codeaurora.org \
--cc=iommu@lists.linux-foundation.org \
--cc=robin.murphy@arm.com \
--cc=sspatil@android.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