From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: Tegra DRM device tree bindings Date: Wed, 27 Jun 2012 07:52:24 +0200 Message-ID: <20120627055224.GA8470@avionic-0098.adnet.avionic-design.de> References: <20120626105513.GA9552@avionic-0098.mockup.avionic-design.de> <20120626160224.40ba10a26e3dd3a56b1f312c@nvidia.com> <20120626140033.GC1115@avionic-0098.mockup.avionic-design.de> <23B010BBA481A74B98487467C29BA57BF2361DA3AA@HKMAIL01.nvidia.com> <4FEA6E09.30800@nvidia.com> <23B010BBA481A74B98487467C29BA57BF2361DA3C4@HKMAIL01.nvidia.com> <4FEA7472.7050201@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2598876119013372781==" Return-path: In-Reply-To: <4FEA7472.7050201-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Stephen Warren Cc: "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , Mark Zhang , "dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org --===============2598876119013372781== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="tThc/1wpZn/ma/RB" Content-Disposition: inline --tThc/1wpZn/ma/RB Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 26, 2012 at 08:48:18PM -0600, Stephen Warren wrote: > On 06/26/2012 08:32 PM, Mark Zhang wrote: > >> On 06/26/2012 07:46 PM, Mark Zhang wrote: > >>>>> On Tue, 26 Jun 2012 12:55:13 +0200 > >>>>> Thierry Reding wrote: > >> ... > >>>> I'm not sure I understand how information about the carveout would be > >>>> obtained from the IOMMU API, though. > >>> > >>> I think that can be similar with current gart implementation. Define = carveout as: > >>> > >>> carveout { > >>> compatible =3D "nvidia,tegra20-carveout"; > >>> size =3D <0x10000000>; > >>> }; > >>> > >>> Then create a file such like "tegra-carveout.c" to get these definiti= ons and > >> register itself as platform device's iommu instance. > >> > >> The carveout isn't a HW object, so it doesn't seem appropriate to defi= ne a DT > >> node to represent it. > >=20 > > Yes. But I think it's better to export the size of carveout as a config= urable item. > > So we need to define this somewhere. How about define carveout as a pro= perty of gart? >=20 > There already exists a way of preventing Linux from using certain chunks > of memory; the /memreserve/ syntax. From a brief look at the dtc source, > it looks like /memreserve/ entries can have labels, which implies that a > property in the GART node could refer to the /memreserve/ entry by > phandle in order to know what memory regions to use. That doesn't work, unfortunately. The /memreserve/ label isn't even stored in the DTB. Even DTC throws an error when you try to reference the /memreserve/ by label. Thierry --tThc/1wpZn/ma/RB Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQIcBAEBAgAGBQJP6p+YAAoJEN0jrNd/PrOhtigP/jdZ/e50hngj4djJNp3ZjUc8 IVv9j5TQiSWJ3SgI05lGAvu6NBtHiRQl+SHjNzOAgvTVWYjNXrooDdkEEWakNvHr C77mN5dqH5XasdoPh2YwVKuJbahyvkwmhPoB3NP2WiRL+DVbU8zEmHsQvp3Njqkf ixLbfkP/AidOb1s0TOjRkS97JWb9Is8UMBLpKg6zwKmy6oQ9mlcG0cKq1E06WUnG Y97F50pJPysr5k+g+7U075k6cSdxd/IMONMdFN3Y9CRFrCZpHhkVtZlPNu8eX5+d up+6uWv7Usa5tsnOaSv4pK4+rAXnZZMdfCXjdHosalJ3it/nqFt+1mVyc3fBRFwT NMAP01D11iQvMgXh/EXgQai4EmaeIkiVeMiWTBRm1jldfdjb0pwbjoSciIOgiP/0 WjRKLwpIk8GahhQtB78RMLvfD2ZiGkqAdRnF4mBEQOK44VX1X9/i/b9hCf5cj7hL ozdJBnMWpRJmbD9zukZk4V6Ro5gi6+iOUtfCueW+0DHpSlhSxHWKQZ3C5C9ILLHT UyLwgcwdhqsgg4lWpk6z0ty9YioNT/wgwli2rY2UlhlfW+VMqZUJbsE0erh3xd9C erV54qzBSJHp5b0XxYq9zacHLaiIR/b1KyhykSJ6Z0X2y6QjJPZsToN9zmGStVrq NsLPBrtEVnKCc9LcGdaB =kSpE -----END PGP SIGNATURE----- --tThc/1wpZn/ma/RB-- --===============2598876119013372781== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ iommu mailing list iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org https://lists.linuxfoundation.org/mailman/listinfo/iommu --===============2598876119013372781==--