From: Sudeep Holla <sudeep.holla@arm.com>
To: Marc Zyngier <maz@kernel.org>
Cc: mark.rutland@arm.com, Will Deacon <will@kernel.org>,
suzuki.poulose@arm.com, MSM <linux-arm-msm@vger.kernel.org>,
lkml <linux-kernel@vger.kernel.org>,
valentin.schneider@arm.com, catalin.marinas@arm.com,
ionela.voinescu@arm.com, Neeraj Upadhyay <neeraju@codeaurora.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: AMU extension v1 support for cortex A76, A77, A78 CPUs
Date: Fri, 20 Nov 2020 10:20:42 +0000 [thread overview]
Message-ID: <20201120102042.25caeib3iiuxkogt@bogus> (raw)
In-Reply-To: <1712842eb0767e51155a5396d282102c@kernel.org>
On Fri, Nov 20, 2020 at 08:56:31AM +0000, Marc Zyngier wrote:
> On 2020-11-20 04:30, Neeraj Upadhyay wrote:
> > Hi,
> >
> > For ARM cortex A76, A77, A78 cores (which as per TRM, support AMU)
> > AA64PFR0[47:44] field is not set, and AMU does not get enabled for
> > them.
> > Can you please provide support for these CPUs in cpufeature.c?
>
> If that was the case, that'd be an erratum, and it would need to be
> documented as such. It could also be that this is an optional feature
> for these cores (though the TRM doesn't suggest that).
>
> Can someone at ARM confirm what is the expected behaviour of these CPUs?
IIRC discussion with Ionela long back, we intentionally decided not to
support IMPDEF(pre 8.4 non-architected so called AMUs) on the CPUs listed
in $subject.
--
Regards,
Sudeep
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
prev parent reply other threads:[~2020-11-20 10:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <2cc9dd44-0b4b-94a8-155a-7a2446a1b892@codeaurora.org>
2020-11-20 8:56 ` AMU extension v1 support for cortex A76, A77, A78 CPUs Marc Zyngier
2020-11-20 9:09 ` Vladimir Murzin
2020-11-20 9:54 ` Marc Zyngier
2020-11-20 10:14 ` Vladimir Murzin
2020-11-20 10:13 ` Mark Rutland
2020-11-20 10:20 ` Sudeep Holla [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=20201120102042.25caeib3iiuxkogt@bogus \
--to=sudeep.holla@arm.com \
--cc=catalin.marinas@arm.com \
--cc=ionela.voinescu@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=maz@kernel.org \
--cc=neeraju@codeaurora.org \
--cc=suzuki.poulose@arm.com \
--cc=valentin.schneider@arm.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).