From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH 2/2] iommu: Implement a dummy bus_set_iommu() Date: Wed, 15 Oct 2014 11:10:44 +0200 Message-ID: <20141015091043.GA13162@ulmo> References: <1406897113-20099-1-git-send-email-thierry.reding@gmail.com> <1406897113-20099-2-git-send-email-thierry.reding@gmail.com> <20140818165750.GE9809@8bytes.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="VbJkn9YxBvnuCH5J" Return-path: Content-Disposition: inline In-Reply-To: <20140818165750.GE9809@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org To: Joerg Roedel Cc: iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: iommu@lists.linux-foundation.org --VbJkn9YxBvnuCH5J Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Aug 18, 2014 at 06:57:50PM +0200, Joerg Roedel wrote: > On Fri, Aug 01, 2014 at 02:45:13PM +0200, Thierry Reding wrote: > > From: Thierry Reding > >=20 > > This allows IOMMU drivers to compile even if IOMMU_API is not selected > > and helps improve compile coverage. >=20 > IOMMU drivers usually implement the IOMMU-API, so they have a strong > dependency to it. Why do you want to compile-test an iommu driver > without testing the iommu core-code as well? It seems like I never got back to you on this. The reason here is that for Tegra the IOMMU is part of a larger IP block. The IP block is primarily a memory controller with a bunch of configuration knobs for arbitration, prioritization and whatnot. A smaller part of the device does the IOMMU translation. Therefore the IOMMU implementation would be part of a larger driver, and having this dummy would reduce the amount of #ifdefs required. bus_set_iommu() is also the only function in include/linux/iommu.h that doesn't have a dummy, so it seemed like a natural thing to do. That said, I can work around this being absent for !IOMMU_API. Thierry --VbJkn9YxBvnuCH5J Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJUPjoTAAoJEN0jrNd/PrOhsYwP/An4PQHLxcv3daeOk4FJPBgH N8TNJ944wn7IBW7jPZloebPOsCYzRK0Es7ZYMtrky7WpCtwfsIHo9STD+pCp0kOj 7kHIOOa58kZjVY5emlpdFkMUKE8X50/afa17zQoGsBSKrtpsuIzK8yQ1LFuZgRd3 PleaATreoVwJz8eJvUXtQJWydUewGREGVsQOVp1VMf9K/WO2UEFvj1FUh7o1iCr5 iArS3Ua/50C6JY3udez0ENXIESgj9KWbXxpzMexFv5mjrqi7moUkYrjiBoMA8TnX V941luld7hkVsp2EetrT7U7nZyyEjymHfry/0/SkwIP0Fhvq1qYWf6AiOxWnn8uD XBZJY63DbM0XmPtO04qy0CBZl5HupUX/t0dyaz5ZW0oUaShkeY4bvmvi626Dwxj5 u9WPnJErVvqGWJMXhVddgswyWihTHhRigZFiM88YNaf3Ne21fwFbeFhZiLxBtZsu jkkrknj1gwgx16Y5Yqk92ZwhLsAZNhh2sZz0lBBKZpjyNVOzbjbx5bTffAQnfsaP vNPYyQQnbcGavCTBxZSyKpOBS5jtsu0ugGrGUWsoKy1h5m3+Pz3XI7ctaiH2qTbf nG/+H+LQOeGVHnmqq0+3hmKHD/gcJUIkAVRECJhCh/yd9oRy2/ip4HFEDS3lEItt gUNuaUWyTZlhuiQflZKz =4LI/ -----END PGP SIGNATURE----- --VbJkn9YxBvnuCH5J--