From: Marc Zyngier <maz@kernel.org>
To: Mark Brown <broonie@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
danielmentz@google.com, saravanak@google.com,
kernel-team@android.com
Subject: Re: [PATCH 5/6] arm64: Add the arm64.nosme command line option
Date: Mon, 27 Jun 2022 19:08:42 +0100 [thread overview]
Message-ID: <87sfnqdln9.wl-maz@kernel.org> (raw)
In-Reply-To: <YrnjBU2WdUvTMkan@sirena.org.uk>
On Mon, 27 Jun 2022 18:04:05 +0100,
Mark Brown <broonie@kernel.org> wrote:
>
> [1 <text/plain; us-ascii (7bit)>]
> On Mon, Jun 27, 2022 at 04:14:11PM +0100, Marc Zyngier wrote:
>
> > +.Linit_sme: /* SME register access and priority mapping */
> > + msr cptr_el2, x0 // Disable SME traps
> > + bic x0, x0, #CPTR_EL2_TSM
> > + msr cptr_el2, x0
>
> Should the first msr there be a mrs? If not it should probably have a
> comment explaining what it's doing.
Duh. Copy-paste programming, I'm sure it'll go far. :-/
>
> > + mov x1, #0 // SMCR controls
> > +
> > + mrs_s x2, SYS_ID_AA64SMFR0_EL1
> > + ubfx x2, x2, #ID_AA64SMFR0_FA64_SHIFT, #1 // Full FP in SM?
> > + cbz x2, .Lskip_sme_fa64
>
> I'm sure any firmware authors who enable SME will remember to also
> enable FA64 if it's supported in their hardware!
I could add check the override here too. It is a bit ugly as SMFR0
isn't encoded as 4 bit features, but hey, why not.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-06-27 18:09 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-27 15:14 [PATCH 0/6] arm64: Disabling SVE/SME from the command-line Marc Zyngier
2022-06-27 15:14 ` [PATCH 1/6] arm64: Rename the VHE switch to "finalise_el2" Marc Zyngier
2022-06-27 15:14 ` [PATCH 2/6] arm64: Save state of HCR_EL2.E2H before switch to EL1 Marc Zyngier
2022-06-27 15:14 ` [PATCH 3/6] arm64: Allow sticky E2H when entering EL1 Marc Zyngier
2022-06-27 15:14 ` [PATCH 4/6] arm64: Factor out checking of a feature against the override into a macro Marc Zyngier
2022-06-28 11:28 ` Mark Brown
2022-06-29 15:46 ` Marc Zyngier
2022-06-29 16:00 ` Mark Brown
2022-06-27 15:14 ` [PATCH 5/6] arm64: Add the arm64.nosme command line option Marc Zyngier
2022-06-27 17:04 ` Mark Brown
2022-06-27 18:08 ` Marc Zyngier [this message]
2022-06-27 18:20 ` Mark Brown
2022-06-27 15:14 ` [PATCH 6/6] arm64: Add the arm64.nosve " Marc Zyngier
2022-06-27 17:08 ` Mark Brown
2022-06-27 15:18 ` [PATCH 0/6] arm64: Disabling SVE/SME from the command-line Mark Brown
2022-06-27 15:30 ` Marc Zyngier
2022-06-27 16:49 ` Mark Brown
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=87sfnqdln9.wl-maz@kernel.org \
--to=maz@kernel.org \
--cc=ardb@kernel.org \
--cc=broonie@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=danielmentz@google.com \
--cc=kernel-team@android.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=saravanak@google.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).