From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Wed, 28 Jan 2015 13:53:55 +0000 Subject: [RFC PATCH 3/5] iommu: implement common IOMMU ops for DMA mapping In-Reply-To: <20150127123809.GJ30345@8bytes.org> References: <09e5515a9afcb3235f4c425520cd18a6032d31b4.1421086706.git.robin.murphy@arm.com> <20150127002116.GI30345@8bytes.org> <54C7843B.3000605@arm.com> <20150127123809.GJ30345@8bytes.org> Message-ID: <20150128135355.GO1569@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jan 27, 2015 at 12:38:09PM +0000, Joerg Roedel wrote: > On Tue, Jan 27, 2015 at 12:27:39PM +0000, Robin Murphy wrote: > > Laz^WPragmatism - I'm expecting quite a lot of changes to get this > > looking good, so keeping the series as lean as possible to aid > > reviewing/rebasing/etc. seemed sensible. In the same vein, since the > > other architectures already have code that works, my priority is > > getting something in place to fill the gap in arm64 (my current > > remit is "get the SMMUs on Juno working"); it seemed logical to > > minimise disruption and dependencies by aiming to get this merged > > with the one user, then start porting the others (and making the > > inevitable necessary tweaks) once it's in. > > > > I'll adjust the commit message to make that clearer - on re-reading > > it, it does come across as rather vague about that intent. > > Yeah, probably we can add other architectures later (like x86). But can > you at least merge it with the existing version of this for ARM32? That > should be easier to achieve than extending it for x86 by now and we do > not end up with two similar implementations. +1 on that front. We've already had some breakage by using the arm_iommu_* API for the automatic DMA mapping bits, so I'd love to have dma-mapping use the same core code between arm and arm64 as soon as we can, leaving the ARM-specific API for the (hopefully diminishing) set of explicit callers. Will