Received: by 2002:a05:6a11:4021:0:0:0:0 with SMTP id ky33csp2343098pxb; Fri, 17 Sep 2021 07:46:08 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzsJa0HaBqtNfyZ7hpx5jr2Tf4+3mHdo32mqymgjdxr9iXnwinBjbiy7gCFRyjCs/iTfmE9 X-Received: by 2002:a17:906:5855:: with SMTP id h21mr12339874ejs.230.1631889966355; Fri, 17 Sep 2021 07:46:06 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1631889966; cv=none; d=google.com; s=arc-20160816; b=ePIHl1BM15ZRQRgDb0t+BfxmU9DcR1YcVuY09owmnz43BrmvPSsCRwVsRDNkQAMWed dvpuIyfNJ0lueGYlrgPB7kV2/JlswHYcPe8eHuqATIwahfqwHiwfXLgu8jfWM+/6l76u +H3bsIv03IYWPjkGRihEhtg/mLnhL/zC/Gha4c92dQ6J01Lu1+MQcafO47lMIhqFZGTu 74G0AKlqXJaoxktZdxHauVWpfsWoSCC2xadsQAJcykK9561ebyYc3MXeC4zur8IB8BN4 SUS+KFXAlimNCeENAHK2U6g6UafincptWtn4EvsuN4C5L5Xp/658WT8UNYHunkLVAPQQ +6MA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:date:cc:to:from:subject :message-id; bh=7c1Xm1lxqPKg4wDZ+pJIZbIzsRDZfCxRo2nuKYI0O/0=; b=iv49Z9fcoI80B9YxKWhzP8xOztuXcqN6SPghLd1VarDGFbMDnlGSO9mxhNiHWaJT/T bJxEabWYwWUNljnBnwAt0k5Mp5frUQB9P3+8S+SJaZ09ameuF8r5cz66kpBr5HHnAAZS ZBn+CJBS1p6ybrNOOv6opkzlcc0VH90CLpPj1HqEPfpzUVDslUFFQ5SP4E7QH4O70Zi5 8eSINRs+R+LVun+xxXSGNPuschd5jpY9Cs9E75ZNEEU48/Ir94liihPxq7nQxqjfiZ5b cPtboqnCQhRcBszoNyMxGOeYSxwfGYKfovHRcmxAXU7UYdlK2rWhQdmHkL0frRfCy2hz vu3w== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id gn42si7345739ejc.391.2021.09.17.07.45.39; Fri, 17 Sep 2021 07:46:06 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244528AbhIQMk4 (ORCPT + 99 others); Fri, 17 Sep 2021 08:40:56 -0400 Received: from gate.crashing.org ([63.228.1.57]:38147 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244698AbhIQMkq (ORCPT ); Fri, 17 Sep 2021 08:40:46 -0400 Received: from ip6-localhost (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 18HCXk9i027608; Fri, 17 Sep 2021 07:33:47 -0500 Message-ID: <55941ad30ce5515e6955565e3fa155f6caa2a896.camel@kernel.crashing.org> Subject: Re: [PATCH] powerpc: warn on emulation of dcbz instruction From: Benjamin Herrenschmidt To: David Laight , "'Christophe Leroy'" , Paul Mackerras , Michael Ellerman Cc: "linux-kernel@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , Stan Johnson , Finn Thain Date: Fri, 17 Sep 2021 22:33:46 +1000 In-Reply-To: <2fc6953808854149965e60f340eca94b@AcuMS.aculab.com> References: <62b33ca839f3d1d7d4b64b6f56af0bbe4d2c9057.1631716292.git.christophe.leroy@csgroup.eu> <2c0fd775625c76c4dd09b3e923da4405a003f3bd.camel@kernel.crashing.org> <43f736d4-8625-2848-786f-79b902d5c753@csgroup.eu> <2fc6953808854149965e60f340eca94b@AcuMS.aculab.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2021-09-16 at 14:36 +0000, David Laight wrote: > > Does userspace accesses non-cached memory directly ? > > > It probably can if a driver mmaps PCI space directly into user space. > > That certainly works on x86-64. The posterchild for that is Xorg Cheers, Ben.