From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Date: Thu, 3 May 2018 07:47:32 +0100 From: James Hogan To: Christoph Hellwig Subject: Re: [PATCH 11/13] mips, unicore32: swiotlb doesn't need sg->dma_length Message-ID: <20180503064731.GA3971@jamesdev> References: <20180425051539.1989-1-hch@lst.de> <20180425051539.1989-12-hch@lst.de> <20180502222017.GC20766@jamesdev> <20180503035643.GA9781@lst.de> MIME-Version: 1.0 In-Reply-To: <20180503035643.GA9781@lst.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mips@linux-mips.org, sstabellini@kernel.org, Konrad Rzeszutek Wilk , linux-pci@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, sparclinux@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: multipart/mixed; boundary="===============5887177435862520522==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: --===============5887177435862520522== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="CE+1k2dSO48ffgeK" Content-Disposition: inline --CE+1k2dSO48ffgeK Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 03, 2018 at 05:56:43AM +0200, Christoph Hellwig wrote: > On Wed, May 02, 2018 at 11:20:18PM +0100, James Hogan wrote: > > On Wed, Apr 25, 2018 at 07:15:37AM +0200, Christoph Hellwig wrote: > > > Only mips and unicore32 select CONFIG_NEED_SG_DMA_LENGTH when building > > > swiotlb. swiotlb itself never merges segements and doesn't accesses = the > > > dma_length field directly, so drop the dependency. > >=20 > > Is that at odds with Documentation/DMA-API-HOWTO.txt, which seems to > > suggest arch ports should enable it for IOMMUs? >=20 > swiotlb isn't really an iommu.. That being said iommus don't have to > merge segments either if they don't want to, and we have various > implementations that don't. The whole dma api documentation needs > a major overhaul, including merging the various files and dropping a lot > of dead wood. It has been on my todo list for a while, with an inner > hope that someone else would do it before me. Okay, for MIPS: Acked-by: James Hogan Cheers James --CE+1k2dSO48ffgeK Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEARYIAB0WIQS7lRNBWUYtqfDOVL41zuSGKxAj8gUCWuqwggAKCRA1zuSGKxAj 8jJ0AQDBwGZ2k1NphYwyh6OgPS7IN3FDLAFiO2iFddGI2zSf4AEA9hgbj9kgtHKd 8c/TTL4ZMY/xIMHoCb/jXAC1q13gig8= =IGGZ -----END PGP SIGNATURE----- --CE+1k2dSO48ffgeK-- --===============5887177435862520522== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============5887177435862520522==--