From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 66C13C433EF for ; Fri, 7 Jan 2022 16:02:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=8Uwcb+3IAh8MZxb8ktgjMcxjsvp7+RC8QE8I4R2Mkd4=; b=4kc+XlfS/Uk24o Raf85LIS2HUBTdUNZzFQUJRN1JkCtbnNY9duqczpaK4uBdNn9f9VeEa4ACJFvdtRFGgcbCsFYsckA gMJTds0HDvGo6chedkKCWgrjWc9rpe/5FGJrUCdgW89hqiFpnSOqDhyQ83piAhwnECSfoH79/TdRp ASYOIfLQIc/J2r5mxazwPf+txq1ZIjp8a1DIFAPO5Zrksa8JzQrFJCj8emXEGccBPMX4resoS1OnO FQE7AxnBjEeQ4+Zuf84VEMM641RAlrginUbCBTTQL0Tu0NJ3tieHv9OXnaYg6CH4GolZeT39HpKfT zg5mDpK+utAEuZqpJRuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n5rfz-004ZTP-Pe; Fri, 07 Jan 2022 16:01:11 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n5rfw-004ZRn-4W for linux-arm-kernel@lists.infradead.org; Fri, 07 Jan 2022 16:01:09 +0000 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 E190D13D5; Fri, 7 Jan 2022 08:01:06 -0800 (PST) Received: from donnerap.arm.com (donnerap.cambridge.arm.com [10.1.196.172]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A17663F66F; Fri, 7 Jan 2022 08:01:05 -0800 (PST) From: Andre Przywara To: Will Deacon , Catalin Marinas Cc: Marc Zyngier , Mark Rutland , Jonathan Corbet , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 0/2] arm64: booting.rst: Clarify EL2 and cover v8-R64 Date: Fri, 7 Jan 2022 16:00:54 +0000 Message-Id: <20220107160056.322141-1-andre.przywara@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220107_080108_250061_E224B38C X-CRM114-Status: GOOD ( 11.98 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, clarify the wording of the ARM64 boot protocol requirements, to both cater for the introduction of secure EL2 in Armv8.4, but also for the addition of the Armv8-R64 architecture branch. There is an ARM ARM supplement for v8-R64[1], and also a free model[2]. On top of those clarifications, there are at least two other issues to consider for v8-R64 on Linux, I wonder if those should be documented somewhere, although I doubt that booting.rst is the right place: - Linux clears the NS/NSTable bit in the PTEs. In non-secure world those bits are ignored, but when in secure world this means "secure PA". That luckily matches the design here (secure-only), but we should avoid re-purposing those bits in the future (which would be technically possible when running only non-secure). - The GIC needs to be implemented using a "single Security state" for the Linux GIC driver to work. The model mentioned above defaults to a security aware GIC, so needs to be told off using the command line. I wonder if this is should be explicitly mentioned somewhere, to avoid disappointment by implementors later. I'd be grateful for any hint whether to state those things and where to put them. Cheers, Andre [1] https://developer.arm.com/documentation/ddi0600/latest/ [2] https://developer.arm.com/tools-and-software/simulation-models/fixed-virtual-platforms/arm-ecosystem-models Andre Przywara (2): arm64: booting.rst: Clarify on requiring non-secure EL2 arm64: booting.rst: Cover Armv8-R64 Documentation/arm64/booting.rst | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel