From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A832079C8 for ; Thu, 16 Feb 2023 16:02:07 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0D93F113E; Thu, 16 Feb 2023 08:02:50 -0800 (PST) Received: from e126864.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8AF763F881; Thu, 16 Feb 2023 08:02:04 -0800 (PST) From: Kristina Martsenko To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Cc: Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu , Mark Rutland , Mark Brown , Luis Machado , Vladimir Murzin , linux-kernel@vger.kernel.org Subject: [PATCH 10/10] arm64: mops: allow disabling MOPS from the kernel command line Date: Thu, 16 Feb 2023 16:00:12 +0000 Message-Id: <20230216160012.272345-11-kristina.martsenko@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230216160012.272345-1-kristina.martsenko@arm.com> References: <20230216160012.272345-1-kristina.martsenko@arm.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Make it possible to disable the MOPS extension at runtime using the kernel command line. This can be useful for testing or working around hardware issues. Signed-off-by: Kristina Martsenko --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ arch/arm64/kernel/idreg-override.c | 2 ++ 2 files changed, 5 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 6cfa6e3996cf..ee86fe17352d 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -408,6 +408,9 @@ arm64.nosme [ARM64] Unconditionally disable Scalable Matrix Extension support + arm64.nomops [ARM64] Unconditionally disable Memory Copy and Memory + Set instructions support + ataflop= [HW,M68k] atarimouse= [HW,MOUSE] Atari Mouse diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c index d833d78a7f31..d13ae90042cb 100644 --- a/arch/arm64/kernel/idreg-override.c +++ b/arch/arm64/kernel/idreg-override.c @@ -123,6 +123,7 @@ static const struct ftr_set_desc isar2 __initconst = { .fields = { FIELD("gpa3", ID_AA64ISAR2_EL1_GPA3_SHIFT, NULL), FIELD("apa3", ID_AA64ISAR2_EL1_APA3_SHIFT, NULL), + FIELD("mops", ID_AA64ISAR2_EL1_MOPS_SHIFT, NULL), {} }, }; @@ -174,6 +175,7 @@ static const struct { "id_aa64isar1.gpi=0 id_aa64isar1.gpa=0 " "id_aa64isar1.api=0 id_aa64isar1.apa=0 " "id_aa64isar2.gpa3=0 id_aa64isar2.apa3=0" }, + { "arm64.nomops", "id_aa64isar2.mops=0" }, { "arm64.nomte", "id_aa64pfr1.mte=0" }, { "nokaslr", "kaslr.disabled=1" }, }; -- 2.25.1