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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27999C433F5 for ; Fri, 7 Oct 2022 13:54:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229731AbiJGNyd (ORCPT ); Fri, 7 Oct 2022 09:54:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229508AbiJGNyc (ORCPT ); Fri, 7 Oct 2022 09:54:32 -0400 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F3F1CC822B; Fri, 7 Oct 2022 06:54:30 -0700 (PDT) Received: by mail-ej1-x634.google.com with SMTP id ot12so11539156ejb.1; Fri, 07 Oct 2022 06:54:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=Enx4RjQIyhd33IM+TyBELZC95J59S4Pgr5DS3EUuMxI=; b=gpj8FDZDpI7ZZ947ym7dXZiNVjveu/V+u1fISf6SmQWJg2gbqTO0XOG+EmXfZaVTIT 5Kzj5pNupn6gpoaHds0HBtixiVNwiN3NbX6L83pCT/MnChWvT+9+P2DiAgZH67g/Di1L Lc8JeHvrl0E/i0R0cY+XkHRAS9Uhy2Q8MJ4Mm7kV3LaNoF2F1hGCh80L0nQCgoNd9mFT Ji+cPG9OXVLcelxI8y/PSz3JZfu6vaeQX2mvqa5NG457ajgkycuhmoGrMD2HU61p4ErC he/0JMcHbyEXa0vIWCtNfvBcBgsWMQEcvvhmk8mr4ZoH1Jc5sdG4eciwGLjTv6XdfMzw HebA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Enx4RjQIyhd33IM+TyBELZC95J59S4Pgr5DS3EUuMxI=; b=fmHByDzOh4r+HBRK/3K1hCL7R8Zw7zxH5QeN0m/esintOjGk0y8wSelNMWsT+tK3K/ CV7QjDC84wtlmJFwQIogVsiD8Fzg2DV4OgobDN2jdEkbMiAE/TP/kmB6CIVbwQ/GLHht xDA38E9qd7G0lnCQjErTa9wB17rAbMc2iTRj2dunn2/ApfOe7xUauI06PYBn2cYXepgm BCDvprrgbDPFJ5rliXP6qfBNbDomKhVYzTq9HZEbk/G48D3iaFBINw5S3UfHLhXELe6+ YEMyCJcyMJtCbfYe01tFW2YbuJfIKz+1dK6SEa9oeiNXNL0AQGGDvGCgwB1RjCjfTQ8s aAjA== X-Gm-Message-State: ACrzQf3bfq5k5FDba0DeofUjA4MxW68NTashXBIHIp7PnYDMe1HXmqk0 MMy8REQG2Y8SJ6aiSPx8Ids= X-Google-Smtp-Source: AMsMyM7La77T3ZitZ18KvtNZX+eTUrTaeesjPgbUf2RaeFhRX5epUFC4Oz9+762DvbFsno6Xj8g/rw== X-Received: by 2002:a17:907:847:b0:77f:f489:cc25 with SMTP id ww7-20020a170907084700b0077ff489cc25mr4192567ejb.80.1665150869489; Fri, 07 Oct 2022 06:54:29 -0700 (PDT) Received: from orome (p200300e41f201d00f22f74fffe1f3a53.dip0.t-ipconnect.de. [2003:e4:1f20:1d00:f22f:74ff:fe1f:3a53]) by smtp.gmail.com with ESMTPSA id f12-20020a17090660cc00b007415f8ffcbbsm1269503ejk.98.2022.10.07.06.54.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Oct 2022 06:54:28 -0700 (PDT) Date: Fri, 7 Oct 2022 15:54:26 +0200 From: Thierry Reding To: Robin Murphy Cc: Rob Herring , Joerg Roedel , Will Deacon , Nicolin Chen , Krishna Reddy , Dmitry Osipenko , Alyssa Rosenzweig , Janne Grunau , Sameer Pujar , devicetree@vger.kernel.org, iommu@lists.linux-foundation.org, linux-tegra@vger.kernel.org, asahi@lists.linux.dev, Rob Herring Subject: Re: [PATCH v9 1/5] dt-bindings: reserved-memory: Document iommu-addresses Message-ID: References: <20220923123557.866972-1-thierry.reding@gmail.com> <20220923123557.866972-2-thierry.reding@gmail.com> <3fb949ad-74c4-1bac-7e14-5d056afcef5f@arm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="5W5c90u2fS2v03qz" Content-Disposition: inline In-Reply-To: <3fb949ad-74c4-1bac-7e14-5d056afcef5f@arm.com> User-Agent: Mutt/2.2.7 (2022-08-07) Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org --5W5c90u2fS2v03qz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 07, 2022 at 02:45:31PM +0100, Robin Murphy wrote: > On 2022-09-23 13:35, Thierry Reding wrote: > > From: Thierry Reding > >=20 > > This adds the "iommu-addresses" property to reserved-memory nodes, which > > allow describing the interaction of memory regions with IOMMUs. Two use- > > cases are supported: > >=20 > > 1. Static mappings can be described by pairing the "iommu-addresses" > > property with a "reg" property. This is mostly useful for adopting > > firmware-allocated buffers via identity mappings. One common use- > > case where this is required is if early firmware or bootloaders > > have set up a bootsplash framebuffer that a display controller is > > actively scanning out from during the operating system boot > > process. > >=20 > > 2. If an "iommu-addresses" property exists without a "reg" property, > > the reserved-memory node describes an IOVA reservation. Such memo= ry > > regions are excluded from the IOVA space available to operating > > system drivers and can be used for regions that must not be used = to > > map arbitrary buffers. >=20 > Bah, I've only just realised: don't we also need to change the "oneOf: > required: ..." schema to permit "iommu-addresses" without "reg" or "size"? Hm... good point. I think at least we'll want another: - required: - iommu-addresses in there. I wonder if we also need to avoid the combination of "size" and "iommu-addresses". When "size" is specified, is it guaranteed that those regions will be allocated before the direct mapping needs to be created? Thierry --5W5c90u2fS2v03qz Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAmNAL5IACgkQ3SOs138+ s6HMjg/9Ez5oe7o7RKjlGxLRasyNNnpD5dUT5ZmEPcxWBlLBs+6fYqmvVi5DycrV 857CsTJED2/fHahH5TQqsUJmQ4jWtS7Z9Aw74dEMjVqAAtJOmzT0nAyXrgSSaV4E EoOqSM8O++HDS8qUlFqI7CJMXpuUv9hfoDit0m4tSg6fFPKNO5fhWg8oNAgXaKqQ MhBZyLjb0dqCFP/2tfLR0PoLhYv9p4kfu/tcH2HNbScAQDIb61yRRro/bw+q3ABn a63qkZlW0ow8MepXiTfqVbZVToWrP6aSrIAgDgQhi4eQOr4WiHHS0U/t2atgW0Hc LNLC534Hii+aIYSNK6xjDtvbEp2JS0jBVIqpJr6dCOY7jnsGLLwa5GJeNRaPbksE XZ3QvChk9RGv7plPjIVAf23kDethEZEyfEOB93czUH1yQ97+zYQFbNJ06hrjYy0f JbZ6pehcwEiP6PfkP54hzUBsgZrxu6a6INYvxArsEywj0IGhxpzLd/7yWbZ3sewm FQQ03w4RguTfAZBog9+ckWCJKJQId9N2lexIT0XU5vMBZvj06yQdXOxLqTsPs24M rF2efBe1iCzIOxx7O/ki11AJhTAhLMAbblT75FtJfLaL+v8XdkyjEpx/iz8M+MUu hus7GIQTd7f6SpYF77unDhcBvJKeT9LQVucyaEtKo84eCFhDIqA= =3sh+ -----END PGP SIGNATURE----- --5W5c90u2fS2v03qz--