From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [RFC 04/10] memory: Add Tegra124 memory controller support Date: Fri, 27 Jun 2014 15:33:28 -0600 Message-ID: <53ADE328.1080005@wwwdotorg.org> References: <1403815790-8548-1-git-send-email-thierry.reding@gmail.com> <1403815790-8548-5-git-send-email-thierry.reding@gmail.com> <20140627124638.7ec150cca163c89727b8953f@nvidia.com> <20140627110811.GD2797@ulmo> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7369199666262110692==" Return-path: In-Reply-To: <20140627110811.GD2797@ulmo> 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: Thierry Reding , Hiroshi DOyu Cc: Mark Rutland , Olav Haugan , Pawel Moll , Arnd Bergmann , Ian Campbell , Grant Grundler , Rhyland Klein , Will Deacon , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Marc Zyngier , Allen Martin , Rob Herring , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Paul Walmsley , Kumar Gala , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Cho KyongHo , Dave Martin , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: devicetree@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --===============7369199666262110692== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="iRP0KUiPV5PFsE2Td3VmAJUehJcledoiQ" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --iRP0KUiPV5PFsE2Td3VmAJUehJcledoiQ Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 06/27/2014 05:08 AM, Thierry Reding wrote: > On Fri, Jun 27, 2014 at 12:46:38PM +0300, Hiroshi DOyu wrote: >> >> Thierry Reding writes: >> >>> From: Thierry Reding >>> >>> The memory controller on NVIDIA Tegra124 exposes various knobs that c= an >>> be used to tune the behaviour of the clients attached to it. >>> >>> Currently this driver sets up the latency allowance registers to the = HW >>> defaults. Eventually an API should be exported by this driver (via a >>> custom API or a generic subsystem) to allow clients to register laten= cy >>> requirements. >>> >>> This driver also registers an IOMMU (SMMU) that's implemented by the >>> memory controller. >>> >>> Signed-off-by: Thierry Reding >>> --- >>> drivers/memory/Kconfig | 9 + >>> drivers/memory/Makefile | 1 + >>> drivers/memory/tegra124-mc.c | 1945 ++++++++++++++++++++= ++++++++++ >>> include/dt-bindings/memory/tegra124-mc.h | 30 + >>> 4 files changed, 1985 insertions(+) >>> create mode 100644 drivers/memory/tegra124-mc.c >>> create mode 100644 include/dt-bindings/memory/tegra124-mc.h >> >> I prefer reusing the existing SMMU and having MC and SMMU separated >> since most of SMMU code are not different from functionality POV, and >> new MC features are quite independent of SMMU. >> >> If it's really convenient to combine MC and SMMU into one driver, we >> could move "drivers/iomm/tegra-smmu.c" here first, and add MC features= >> on the top of it. >=20 > I'm not sure if we can do that, since the tegra-smmu driver is > technically used by Tegra30 and Tegra114. We've never really made use o= f > it, but there are device trees in mainline releases that contain the > separate SMMU node. The existing DT nodes do nothing more than instantiate the driver. However, IIUC nothing actually uses the driver for any purpose, so if we simply deleted those nodes or changed them incompatibly, there'd be no functional difference. Perhaps this is stretching DT ABIness very slightly, but I think it makes no practical difference. --iRP0KUiPV5PFsE2Td3VmAJUehJcledoiQ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJTreMoAAoJEJuNpwkmVCGchyMP/RMvyiKBagbYiO7NxlbVm0El as1+Vf95u18zvTQkYpLCj4mwwAB0WQ1F4gQPrlk8DeLVVgiK0cg3FJfn29y2ufLK bjXWXO9Lq2UtL2MP3fZmttkYUi6SLTsP/NCQVLPPbheAQyJKGjSextI8/lKV8uq1 kufVLFDd+qdYNdM/VJaso1Q6oUn5PB43sft57JudZovzLrAVFfm/6sQXwwTqYfFw W2CZ+zKBnt2L8L1KBaVvFvZGiizxejvfApgbUrfNhY/q8v0330fU8htg+9z1mgjY isfeEllFK0wV+Vmq/v2cFDMC3OhpLZp5nq5/fhCAJB2/HNXhP8mEypKeKQHeFvey TjciyQ3MFI9Rig41o/qKVt5w8Ih8WvY7NCm+6n/yukBfFn8k4cHLteBbrjU6+qhc +lJ/tmkXgHqF+u+J3iJdmblOrjkLWhDTxQCRpj1M+5gxpdCIXdmMUGRY1TGiqzzm Wx/GHJ2EdujyWjmrYsO62WwQrRtb2nutytBHk7VCtghmEqWwUOx5fsc/hH4zDrwl oxQO9L5Knt7tpqoQOqXpYQpoxdcwfMmU6DGi0CVWMncISqAL9JZG+f/eY/wxrgpu L5QsAx5+19pEtuxeFvTelC9APzNz5ccOl0joRBvYybkqjstsmTd5GxAF4moO1NwQ 2v8lj49ngpi/pssv2j2A =Ovyz -----END PGP SIGNATURE----- --iRP0KUiPV5PFsE2Td3VmAJUehJcledoiQ-- --===============7369199666262110692== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============7369199666262110692==--