From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id AE5D06B0008 for ; Tue, 17 Apr 2018 08:54:01 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id f19so11054416pfn.6 for ; Tue, 17 Apr 2018 05:54:01 -0700 (PDT) Received: from ozlabs.org (ozlabs.org. [2401:3900:2:1::2]) by mx.google.com with ESMTPS id u14si11626503pgq.103.2018.04.17.05.53.59 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 17 Apr 2018 05:53:59 -0700 (PDT) From: Michael Ellerman Subject: Re: [PATCH 01/12] iommu-common: move to arch/sparc In-Reply-To: References: <20180415145947.1248-1-hch@lst.de> <20180415145947.1248-2-hch@lst.de> <20180416.095833.969403163564136309.davem@davemloft.net> Date: Tue, 17 Apr 2018 22:53:53 +1000 Message-ID: <87wox60za6.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Anshuman Khandual , David Miller khandual@linux.vnet.ibm.com Cc: hch@lst.de, konrad.wilk@oracle.com, iommu@lists.linux-foundation.org, x86@kernel.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, linux-ide@vger.kernel.org, linux-mips@linux-mips.org, sparclinux@vger.kernel.org, linux-arm-kernel@lists.infradead.org Anshuman Khandual writes: > On 04/16/2018 07:28 PM, David Miller wrote: >> From: Anshuman Khandual >> Date: Mon, 16 Apr 2018 14:26:07 +0530 >> >>> On 04/15/2018 08:29 PM, Christoph Hellwig wrote: >>>> This code is only used by sparc, and all new iommu drivers should use the >>>> drivers/iommu/ framework. Also remove the unused exports. >>>> >>>> Signed-off-by: Christoph Hellwig >>> >>> Right, these functions are used only from SPARC architecture. Simple >>> git grep confirms it as well. Hence it makes sense to move them into >>> arch code instead. >> >> Well, we put these into a common location and used type friendly for >> powerpc because we hoped powerpc would convert over to using this >> common piece of code as well. >> >> But nobody did the powerpc work. Sorry. >> If you look at the powerpc iommu support, it's the same code basically >> for entry allocation. > > I understand. But there are some differences in iommu_table structure, > how both regular and large IOMMU pools are being initialized etc. So > if the movement of code into SPARC help cleaning up these generic config > options in general, I guess we should do that. But I will leave it upto > others who have more experience in this area. > > +mpe This is the first I've heard of it, I guess it's probably somewhere on Ben's append-only TODO list. Some of the code does look very similar, but not 100%. So someone would need to do some work to reconcile the two and test the result. TBH I doubt we're going to get around to it any time soon. Unless we have a volunteer? cheers