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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB11CC433EF for ; Thu, 30 Sep 2021 19:40:37 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 89F7061A3F for ; Thu, 30 Sep 2021 19:40:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 89F7061A3F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9E3416E3FE; Thu, 30 Sep 2021 19:40:36 +0000 (UTC) Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3BBF26E3FE for ; Thu, 30 Sep 2021 19:40:35 +0000 (UTC) Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 835B41F412A6; Thu, 30 Sep 2021 20:40:33 +0100 (BST) Date: Thu, 30 Sep 2021 21:40:30 +0200 From: Boris Brezillon To: Alyssa Rosenzweig Cc: Rob Herring , Tomeu Vizoso , Alyssa Rosenzweig , Steven Price , Robin Murphy , dri-devel@lists.freedesktop.org Subject: Re: [PATCH] drm/panfrost: Add PANFROST_BO_NO{READ,WRITE} flags Message-ID: <20210930214030.19f63eac@collabora.com> In-Reply-To: References: <20210930184723.1482426-1-boris.brezillon@collabora.com> Organization: Collabora X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, 30 Sep 2021 15:13:29 -0400 Alyssa Rosenzweig wrote: > > + /* Executable implies readable */ > > + if ((args->flags & PANFROST_BO_NOREAD) && > > + !(args->flags & PANFROST_BO_NOEXEC)) > > + return -EINVAL; > > Generally, executable also implies not-writeable. Should we check that? We were allowing it until now, so doing that would break the backward compat, unfortunately. Steve also mentioned that the DDK might use shaders modifying other shaders here [1], it clearly doesn't happen in panfrost, but I think I'd prefer to keep the existing behavior by default, just to be safe. I'll send a patch setting the RO flag on all executable BOs in mesa/panfrost. [1]https://oftc.irclog.whitequark.org/panfrost/2021-09-02