From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 77EBD26296; Wed, 16 Apr 2025 07:11:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744787500; cv=none; b=tYlT0Zua33mqra1qIShytg/oKImbOEZm31F8rJdsHsMPggUdJo5AQlsQvbZR5NK1WOxca5Z31wt+gCtp+Pfmzo/7HM3G51cmMuIRH3SoVSba2gbmCiSOGdOvlFoY6wB5jaEh06Lz6gNz1h8InnOTt6G+I0gkgsxRkkPwZt2QGlc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744787500; c=relaxed/simple; bh=szqjAkZRW2FQzyNwPP2HrTZPgVMC0eK0PojCcr4EVeE=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=q5EHtlP21mrxvA0OPxplxxC9qLda6kpnU5o1c2mIxRsCafs9FrvCwN4ZyZfPFUnxscZvQ2yKQcSrY/o7m5KLdL1ZBb3bI3HSMN5sKzqPFpxHDv9gCPoEaX8JdESj9exOk3LRoHTOTzdQmLBqt/O+uf0Jim5FrEkkjeyQFm8xi44= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Y5hlVazR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Y5hlVazR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA0FCC4CEE2; Wed, 16 Apr 2025 07:11:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744787499; bh=szqjAkZRW2FQzyNwPP2HrTZPgVMC0eK0PojCcr4EVeE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Y5hlVazRgUt0P5iJmGiFXgqESJvp6duOYlAtmxhyV7VbEQcH6RqQlmtge8oz+Q9xF iG/vG9W94rLdVaKbE+dYrhp/VUJdlm7oJxbdLGo7YB+KO4rt0Xe88M/c+Bm23spN24 XuI89yyD95/Y/6+p89b2ALbFhM7Ybt29JDGX+ESMGqjs//lQXYOSPBaJdkXGM2zwjv NpAqY8pYtHZCMe2lX5WJlwlvfMcyRoDbTDPRdUgv7+PhQ3U2iXlsPokgPMLVaV1BhK qvZaepMUX3zP1HtUWaQQYMbQFzAMn5TyTeEK/bPlNHB0CZ1giIX7OdfS9387apm1zV DmqTRqSf0x6Fw== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1u4wvp-005wlp-Da; Wed, 16 Apr 2025 08:11:37 +0100 Date: Wed, 16 Apr 2025 08:11:36 +0100 Message-ID: <86y0w0k2c7.wl-maz@kernel.org> From: Marc Zyngier To: D Scott Phillips Cc: Oliver Upton , Catalin Marinas , James Clark , James Morse , Joey Gouly , Kevin Brodsky , Mark Brown , Mark Rutland , "Rob Herring\ (Arm)" , Shameer Kolothum , Shiqi Liu , Will Deacon , Yicong Yang , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, open list Subject: Re: [PATCH 2/2] arm64: errata: Work around AmpereOne's erratum AC04_CPU_23 In-Reply-To: <864iypgjjc.fsf@scott-ph-mail.amperecomputing.com> References: <20250415154711.1698544-1-scott@os.amperecomputing.com> <20250415154711.1698544-2-scott@os.amperecomputing.com> <864iypgjjc.fsf@scott-ph-mail.amperecomputing.com> 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/29.4 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: scott@os.amperecomputing.com, oliver.upton@linux.dev, catalin.marinas@arm.com, james.clark@linaro.org, james.morse@arm.com, joey.gouly@arm.com, kevin.brodsky@arm.com, broonie@kernel.org, mark.rutland@arm.com, robh@kernel.org, shameerali.kolothum.thodi@huawei.com, shiqiliu@hust.edu.cn, will@kernel.org, yangyicong@hisilicon.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Tue, 15 Apr 2025 23:13:43 +0100, D Scott Phillips wrote: > > Marc Zyngier writes: > > > On Tue, 15 Apr 2025 16:47:11 +0100, > > If the write to HCR_EL2 can corrupt translations, what guarantees that > > such write placed on a page boundary (therefore requiring another TLB > > lookup to continue in sequence) will be able to get to the ISB? > > Hi Marc, I understand now from the core team that an ISB on another page > will be ok as the problem is on the data side only. Are you guaranteed that a younger data access can't be hoisted up and affect things similarly? I don't see anything that would prevent this. Thanks, M. -- Without deviation from the norm, progress is not possible.