From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932761AbcISSlO (ORCPT ); Mon, 19 Sep 2016 14:41:14 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:38841 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932392AbcISSlM (ORCPT ); Mon, 19 Sep 2016 14:41:12 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 19 Sep 2016 14:41:10 -0400 From: bdegraaf@codeaurora.org To: Laura Abbott Cc: catalin.marinas@arm.com, will.deacon@arm.com, james.morse@arm.com, mark.rutland@arm.com, andre.przywara@arm.com, jungseoklee85@gmail.com, apinski@cavium.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org Subject: Re: [RFC] arm64: Ensure proper addressing for ldnp/stnp In-Reply-To: <50fcc549-d785-6332-83bd-292a4f44e8d4@redhat.com> References: <1474306586-25118-1-git-send-email-bdegraaf@codeaurora.org> <50fcc549-d785-6332-83bd-292a4f44e8d4@redhat.com> Message-ID: <13521f9f5ebe1cd0a85bf31b5ad5cba0@codeaurora.org> User-Agent: Roundcube Webmail/1.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016-09-19 14:28, Laura Abbott wrote: > On 09/19/2016 10:36 AM, Brent DeGraaf wrote: >> According to section 6.3.8 of the ARM Programmer's Guide, non-temporal >> loads and stores do not verify that address dependency is met between >> a >> load of an address to a register and a subsequent non-temporal load or >> store using that address on the executing PE. Therefore, context >> switch >> code and subroutine calls that use non-temporally accessed addresses >> as >> parameters that might depend on a load of an address into an argument >> register must ensure that ordering requirements are met by introducing >> a barrier prior to the successive non-temporal access. Add >> appropriate >> barriers whereever this specific situation comes into play. >> > > Was this found by code inspection or is there a (public) exciting test > case to observe this behavior? > > Thanks, > Laura > Code inspection only. Brent