From: Florian Fainelli <f.fainelli@gmail.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Doug Berger <opendmb@gmail.com>,
catalin.marinas@arm.com, Russell King <linux@armlinux.org.uk>,
open list <linux-kernel@vger.kernel.org>,
Florian Fainelli <f.fainelli@gmail.com>,
bcm-kernel-feedback-list@broadcom.com, will@kernel.org,
Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: [PATCH] ARM: spectre-v2: remove Brahma-B53 from hardening
Date: Thu, 31 Oct 2019 15:00:51 -0700 [thread overview]
Message-ID: <20191031220053.2720-1-f.fainelli@gmail.com> (raw)
From: Doug Berger <opendmb@gmail.com>
When the default processor handling was added to the function
cpu_v7_spectre_init() it only excluded other ARM implemented processor
cores. The Broadcom Brahma B53 core is not implemented by ARM so it
ended up falling through into the set of processors that attempt to use
the ARM_SMCCC_ARCH_WORKAROUND_1 service to harden the branch predictor.
Since this workaround is not necessary for the Brahma-B53 this commit
explicitly checks for it and prevents it from applying a branch
predictor hardening workaround.
Fixes: 10115105cb3a ("ARM: spectre-v2: add firmware based hardening")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
arch/arm/mm/proc-v7-bugs.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c
index 9a07916af8dd..a6554fdb56c5 100644
--- a/arch/arm/mm/proc-v7-bugs.c
+++ b/arch/arm/mm/proc-v7-bugs.c
@@ -65,6 +65,9 @@ static void cpu_v7_spectre_init(void)
break;
#ifdef CONFIG_ARM_PSCI
+ case ARM_CPU_PART_BRAHMA_B53:
+ /* Requires no workaround */
+ break;
default:
/* Other ARM CPUs require no workaround */
if (read_cpuid_implementor() == ARM_CPU_IMP_ARM)
--
2.17.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2019-10-31 22:01 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-31 22:00 Florian Fainelli [this message]
2019-11-11 3:33 ` [PATCH] ARM: spectre-v2: remove Brahma-B53 from hardening Florian Fainelli
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=20191031220053.2720-1-f.fainelli@gmail.com \
--to=f.fainelli@gmail.com \
--cc=bcm-kernel-feedback-list@broadcom.com \
--cc=catalin.marinas@arm.com \
--cc=julien.thierry.kdev@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=opendmb@gmail.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).