From: Will Deacon <will@kernel.org>
To: Vennila Megavannan <vemegava@linux.microsoft.com>
Cc: jean-philippe@linaro.org, linux-kernel@vger.kernel.org,
iommu@lists.linux-foundation.org, tyhicks@linux.microsoft.com,
srinath.mannam@broadcom.com,
bcm-kernel-feedback-list@broadcom.com, robin.murphy@arm.com,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] iommu/arm: Add module parameter to set msi iova address
Date: Mon, 21 Sep 2020 21:45:45 +0100 [thread overview]
Message-ID: <20200921204545.GA3811@willie-the-truck> (raw)
In-Reply-To: <20200914181307.117792-1-vemegava@linux.microsoft.com>
On Mon, Sep 14, 2020 at 11:13:07AM -0700, Vennila Megavannan wrote:
> From: Srinath Mannam <srinath.mannam@broadcom.com>
>
> Add provision to change default value of MSI IOVA base to platform's
> suitable IOVA using module parameter. The present hardcoded MSI IOVA base
> may not be the accessible IOVA ranges of platform.
>
> If any platform has the limitaion to access default MSI IOVA, then it can
> be changed using "arm-smmu.msi_iova_base=0xa0000000" command line argument.
>
> Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
> Co-developed-by: Vennila Megavannan <vemegava@linux.microsoft.com>
> Signed-off-by: Vennila Megavannan <vemegava@linux.microsoft.com>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 5 ++++-
> drivers/iommu/arm/arm-smmu/arm-smmu.c | 5 ++++-
> 2 files changed, 8 insertions(+), 2 deletions(-)
This feels pretty fragile. Wouldn't it be better to realise that there's
a region conflict with iommu_dma_get_resv_regions() and move the MSI window
accordingly at runtime?
Will
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2020-09-21 20:45 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-14 18:13 [PATCH v2] iommu/arm: Add module parameter to set msi iova address Vennila Megavannan
2020-09-21 20:45 ` Will Deacon [this message]
2020-09-22 22:37 ` Vennila Megavannan
2020-09-23 6:32 ` Auger Eric
2020-09-28 20:56 ` Will Deacon
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=20200921204545.GA3811@willie-the-truck \
--to=will@kernel.org \
--cc=bcm-kernel-feedback-list@broadcom.com \
--cc=iommu@lists.linux-foundation.org \
--cc=jean-philippe@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=robin.murphy@arm.com \
--cc=srinath.mannam@broadcom.com \
--cc=tyhicks@linux.microsoft.com \
--cc=vemegava@linux.microsoft.com \
/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).