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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52E88C433B4 for ; Thu, 8 Apr 2021 17:18:14 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CA4CB60FEA for ; Thu, 8 Apr 2021 17:18:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CA4CB60FEA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Subject:Cc:To: From:Message-ID:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/S7HaZDSnMw0pG++rb4S4qjAXinznXg0jEZ2KeEIB8c=; b=bgAwZWxm/Ds4TnXCkapkIeldR hhg9XzKcokTBxTiOPDipyicsCtiWm3YGG9CcVTkx82DYTzLawFbGzKHmKLKfaEJbH5MdYwNNiCfrh V23W/leUO2wlTdtJma9oRBlW6ZrYS86Kxp8V93f1BxPZ3Fp38a4HoP+IMX/pbFDUTBiikFhSRzP6C 1ZscV1K+hce9Wr7/F4aeCAwbFUYExn7dSSONa/gdRPnnPmrGSFKxzWNHXUh+Sc5Wxo288Vl425X/w CWiSE1RHuVuhHnKlEEefFYDuz3KsH7gt57x4eWMD6oukFUHa0qfGi4NeKoPMR/WK+7vud440A6n5M e9i82ytwA==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lUYGG-008kio-91; Thu, 08 Apr 2021 17:16:08 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lUY30-008ivG-7t for linux-arm-kernel@lists.infradead.org; Thu, 08 Apr 2021 17:02:28 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B783561131; Thu, 8 Apr 2021 17:02:24 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lUY2v-006MWN-S9; Thu, 08 Apr 2021 18:02:22 +0100 Date: Thu, 08 Apr 2021 18:02:19 +0100 Message-ID: <87r1jkogkk.wl-maz@kernel.org> From: Marc Zyngier To: Mark Brown Cc: Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 3/4] arm64: Require that system registers at all visible ELs be initialized In-Reply-To: <20210401180942.35815-4-broonie@kernel.org> References: <20210401180942.35815-1-broonie@kernel.org> <20210401180942.35815-4-broonie@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: broonie@kernel.org, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210408_180226_491220_B08EF7A8 X-CRM114-Status: GOOD ( 18.66 ) 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 On Thu, 01 Apr 2021 19:09:41 +0100, Mark Brown wrote: > > Currently we require that software at a higher exception level initialise > all registers at the exception level the kernel will be entered prior to > starting the kernel in order to ensure that there is nothing uninitialised > which could result in an UNKNOWN state while running the kernel. The > expectation is that the software running at the highest exception levels > will be tightly coupled to the system and can ensure that all available > features are appropriately initialised and that the kernel can initialise > anything else. > > There is a gap here in the case where new registers are added to lower > exception levels that require initialisation but the kernel does not yet > understand them. Extend the requirement to also include exception levels > below the one where the kernel is entered to cover this. > > Suggested-by: Catalin Marinas > Signed-off-by: Mark Brown Acked-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel