From: Mark Rutland <mark.rutland@arm.com>
To: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Subject: Re: [boot-wrapper PATCH] aarch64: Do not trap PMSNEVFR_EL1
Date: Wed, 18 Aug 2021 15:12:56 +0100 [thread overview]
Message-ID: <20210818141256.GB64368@C02TD0UTHF1T.local> (raw)
In-Reply-To: <20210817163420.813631-1-alexandru.elisei@arm.com>
On Tue, Aug 17, 2021 at 05:34:20PM +0100, Alexandru Elisei wrote:
> FEAT_PMUv1p2 adds a new register, PMSNEVFR_EL1, and a new MDCR_EL3 trap bit
> for it, EnPMSN. Set the bit to 1 to allow lower exception levels direct
> access to the register.
>
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Thanks for this; I have a couple of minor comments below, which I'll fix
up when applying.
> ---
> arch/aarch64/boot.S | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S
> index 2215f7ed3a1f..8951f1e4676a 100644
> --- a/arch/aarch64/boot.S
> +++ b/arch/aarch64/boot.S
> @@ -88,8 +88,12 @@ ASM_FUNC(_start)
> cbz x1, 1f
>
> // Enable SPE for the non-secure world.
> - ldr x1, =(0x3 << 12)
> - orr x0, x0, x1
> + ldr x2, =(0x3 << 12)
> + orr x0, x0, x2
Since we're touching this, I'll make it:
orr x0, x0, #(3 << 12)
> + cmp x1, #3
> + b.lt 1
For consistency, I'll make this `b.lt 1f`
> + // Do not trap PMSNEVFR_EL1.
> + orr x0, x0, #(1 << 36)
For legibility, I'll re-order this as:
// Do not trap PMSNEVFR_EL1 if present.
cmp x1, #3
b.lt 1f
orr x0, x0, #(1 << 36)
Thanks,
Mark.
>
> 1: mrs x1, id_aa64dfr0_el1
> ubfx x1, x1, #44, #4
> --
> 2.32.0
>
_______________________________________________
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:[~2021-08-18 14:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-17 16:34 [boot-wrapper PATCH] aarch64: Do not trap PMSNEVFR_EL1 Alexandru Elisei
2021-08-18 14:12 ` Mark Rutland [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=20210818141256.GB64368@C02TD0UTHF1T.local \
--to=mark.rutland@arm.com \
--cc=alexandru.elisei@arm.com \
--cc=linux-arm-kernel@lists.infradead.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).