From patchwork Sun Jul 16 21:50:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 703932 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4822C001E0 for ; Sun, 16 Jul 2023 21:53:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231136AbjGPVx1 (ORCPT ); Sun, 16 Jul 2023 17:53:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230463AbjGPVxQ (ORCPT ); Sun, 16 Jul 2023 17:53:16 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB67B10DE; Sun, 16 Jul 2023 14:53:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0CDEC60D41; Sun, 16 Jul 2023 21:53:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4103C433C9; Sun, 16 Jul 2023 21:53:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689544388; bh=Z3injfV8td0LqFLeGew+/6AX1Y4kpAJIpTs5MPlZTRs=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=N+Py4rEKJjLcKslfUQhgfO1OLzM2rGuwjpOszMNXo+y2NlpsFHeY3dbTRq/heqKTb wCotmXx42Mh4PFe5yqcrpQXV5HgTXSOOBEZ0RghiFHyfOaEpsg06fHhTe/tHw/6OcC BTi00ukC4eUl1XRMgUsAcmJBP7sjQxXyLeTfrrXdgYTCff4OLLtV6gVZjP8iCXVcKB P6nPf6DSHHfQz0nOcp8DDAG7JTMQcPwLVb6A5VLrHSwjq+I6/Q3R2TD5f/rPdDi8zy 3R8S3ECtvSSDliWtVW2gcieOb6yEb9YfvQqE8rjxrvgADtdRuLMv9zHcIhdhHgr48K TLshLQx2OIL8w== From: Mark Brown Date: Sun, 16 Jul 2023 22:50:59 +0100 Subject: [PATCH 03/35] arm64: Document boot requirements for Guarded Control Stacks MIME-Version: 1.0 Message-Id: <20230716-arm64-gcs-v1-3-bf567f93bba6@kernel.org> References: <20230716-arm64-gcs-v1-0-bf567f93bba6@kernel.org> In-Reply-To: <20230716-arm64-gcs-v1-0-bf567f93bba6@kernel.org> To: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Kees Cook , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy Cc: "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Brown X-Mailer: b4 0.13-dev-099c9 X-Developer-Signature: v=1; a=openpgp-sha256; l=1640; i=broonie@kernel.org; h=from:subject:message-id; bh=Z3injfV8td0LqFLeGew+/6AX1Y4kpAJIpTs5MPlZTRs=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBktGaRKKWoYO6shp83J7bdF2HDjv/deCuL6Bh7YBpr XGGHoyKJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZLRmkQAKCRAk1otyXVSH0DHnB/ 4m4xAjhCNKrOG833NrlQvIqQ8SUd4K5W5qh5Ps/ZgIVd+0dZkeIAFcRu2fAfuuHQl4Sg+SRkRdWPge eeiRzTVTFyv2RXMEQOPvtv1m5NUn4oCojVB4hywZSC/rE9XrRGNDjGZyEOO2ylprq2nf3mDYWjstJh 9jCBGUEEhqXr1LT17uFMA1zEsO7JJeQ33aTE6kDdjYlBrhTZq43pRfEROGeW7Dhgjx3sd6KCVltGCU WGPGxd+7M83m+GVw87chK92IZYO0+Fe1tKdfMfbfNslHg415niWo8ao4Tm76iYPut036lAZhbttboW zekDSpXoOfhPseiRPDqOQA1eWCZErE X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org FEAT_GCS introduces a number of new system registers, we require that access to these registers is not trapped when we identify that the feature is detected. Signed-off-by: Mark Brown --- Documentation/arch/arm64/booting.rst | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/Documentation/arch/arm64/booting.rst b/Documentation/arch/arm64/booting.rst index b57776a68f15..de3679770c64 100644 --- a/Documentation/arch/arm64/booting.rst +++ b/Documentation/arch/arm64/booting.rst @@ -411,6 +411,28 @@ Before jumping into the kernel, the following conditions must be met: - HFGRWR_EL2.nPIRE0_EL1 (bit 57) must be initialised to 0b1. + - For features with Guarded Control Stacks (FEAT_GCS): + + - If EL3 is present: + + - SCR_EL3.GCSEn (bit 39) must be initialised to 0b1. + + - If the kernel is entered at EL1 and EL2 is present: + + - HFGITR_EL2.nGCSEPP (bit 59) must be initialised to 0b1. + + - HFGITR_EL2.nGCSSTR_EL1 (bit 58) must be initialised to 0b1. + + - HFGITR_EL2.nGCSPUSHM_EL1 (bit 57) must be initialised to 0b1. + + - HFGRTR_EL2.nGCS_EL1 (bit 53) must be initialised to 0b1. + + - HFGRTR_EL2.nGCS_EL0 (bit 52) must be initialised to 0b1. + + - HFGWTR_EL2.nGCS_EL1 (bit 53) must be initialised to 0b1. + + - HFGWTR_EL2.nGCS_EL0 (bit 52) must be initialised to 0b1. + The requirements described above for CPU mode, caches, MMUs, architected timers, coherency and system registers apply to all CPUs. All CPUs must enter the kernel in the same exception level. Where the values documented