From: Jason Gunthorpe <jgg@nvidia.com>
To: Shanker Donthineni <sdonthineni@nvidia.com>
Cc: Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-arm-kernel@lists.infradead.org,
Vladimir Murzin <vladimir.murzin@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
Vikram Sethi <vsethi@nvidia.com>,
Jason Sequeira <jsequeira@nvidia.com>
Subject: Re: [PATCH v2] arm64: errata: Workaround NVIDIA Olympus device store/load ordering erratum
Date: Wed, 10 Jun 2026 13:11:44 -0300 [thread overview]
Message-ID: <20260610161144.GU1962447@nvidia.com> (raw)
In-Reply-To: <223c49ee-528c-4750-9885-fd8e0247151e@nvidia.com>
On Wed, Jun 10, 2026 at 08:20:28AM -0500, Shanker Donthineni wrote:
> Based on the existing code comments and after reviewing this path again,
> __const_memcpy_toio_aligned32() and __const_memcpy_toio_aligned64()
> appear to be intended for WC regions. Since the erratum is scoped to
> Device-nGnR* accesses, and WC mappings are Normal-NC on arm64, I don’t
> think the STLR workaround should apply to these helpers by default.
Hmm, unfortunately I think the APIs mix together IO and WC both as
__iomem things. However I recall when I was looking a this everyone
was using it for WC.
Jason
prev parent reply other threads:[~2026-06-10 16:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-05 14:45 [PATCH v2] arm64: errata: Workaround NVIDIA Olympus device store/load ordering erratum Shanker Donthineni
2026-06-10 11:28 ` Will Deacon
2026-06-10 12:50 ` Jason Gunthorpe
2026-06-10 12:53 ` Shanker Donthineni
2026-06-10 13:20 ` Shanker Donthineni
2026-06-10 16:11 ` Jason Gunthorpe [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=20260610161144.GU1962447@nvidia.com \
--to=jgg@nvidia.com \
--cc=catalin.marinas@arm.com \
--cc=jsequeira@nvidia.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=sdonthineni@nvidia.com \
--cc=vladimir.murzin@arm.com \
--cc=vsethi@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.