linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Andre Przywara <andre.przywara@arm.com>
To: Marc Zyngier <maz@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
	Mark Rutland <mark.rutland@arm.com>,
	broonie@kernel.org, kernel-team@android.com
Subject: Re: [AArch64 boot-wrapper][PATCH] aarch64: Enable FGT for EL2
Date: Tue, 4 May 2021 16:19:12 +0100	[thread overview]
Message-ID: <20210504161912.4b570e9d@slackpad.fritz.box> (raw)
In-Reply-To: <20210503120920.1819233-1-maz@kernel.org>

On Mon,  3 May 2021 13:09:20 +0100
Marc Zyngier <maz@kernel.org> wrote:

> We have no intention of handling FGT traps to EL3, so let EL2
> play with the feature directly.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Verified the bits used against the ARM ARM. Also Trusted Firmware does
the same thing, so:

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre

> ---
> 
> Notes:
>     Needed to boot Linux 5.13 at EL2.
> 
>  arch/aarch64/boot.S | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S
> index e47cf59..fd7133d 100644
> --- a/arch/aarch64/boot.S
> +++ b/arch/aarch64/boot.S
> @@ -54,6 +54,13 @@ _start:
>  	cbz	x1, 1f
>  
>  	orr	x0, x0, #(1 << 34)		// TME enable
> +1:
> +	/* Enable FGT if present */
> +	mrs	x1, id_aa64mmfr0_el1
> +	ubfx	x1, x1, #56, #4
> +	cbz	x1, 1f
> +
> +	orr	x0, x0, #(1 << 27)		// FGT enable
>  1:
>  #ifndef KERNEL_32
>  	orr	x0, x0, #(1 << 10)		// 64-bit EL2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2021-05-04 15:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-03 12:09 [AArch64 boot-wrapper][PATCH] aarch64: Enable FGT for EL2 Marc Zyngier
2021-05-04 15:19 ` Andre Przywara [this message]
2021-05-04 15:29 ` Sudeep Holla
2021-05-04 15:31 ` Mark Rutland

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=20210504161912.4b570e9d@slackpad.fritz.box \
    --to=andre.przywara@arm.com \
    --cc=broonie@kernel.org \
    --cc=kernel-team@android.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=mark.rutland@arm.com \
    --cc=maz@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).