From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: a saner API for allocating DMA addressable pages v3 Date: Mon, 21 Sep 2020 08:36:28 +0200 Message-ID: <20200921063628.GB18349@lst.de> References: <20200915155122.1768241-1-hch@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20200915155122.1768241-1-hch-jcswGhMUV9g@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Sender: "iommu" To: Mauro Carvalho Chehab , Thomas Bogendoerfer , "James E.J. Bottomley" , Joonyoung Shim , Seung-Woo Kim , Ben Skeggs , Marek Szyprowski , Tomasz Figa , Matt Porter , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Cc: alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org, linux-samsung-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-parisc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mips-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Stefan Richter , netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux1394-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: nouveau.vger.kernel.org Any comments? Thomas: this should be identical to the git tree I gave you for mips testing, and you add your tested-by (and reviewd-by tags where applicable)? Helge: for parisc this should effectively be the same as the first version, but I've dropped the tested-by tags due to the reshuffle, and chance you could retest it? On Tue, Sep 15, 2020 at 05:51:04PM +0200, Christoph Hellwig wrote: > Hi all, > > this series replaced the DMA_ATTR_NON_CONSISTENT flag to dma_alloc_attrs > with a separate new dma_alloc_pages API, which is available on all > platforms. In addition to cleaning up the convoluted code path, this > ensures that other drivers that have asked for better support for > non-coherent DMA to pages with incurring bounce buffering over can finally > be properly supported. > > As a follow up I plan to move the implementation of the > DMA_ATTR_NO_KERNEL_MAPPING flag over to this framework as well, given > that is also is a fundamentally non coherent allocation. The replacement > for that flag would then return a struct page, as it is allowed to > actually return pages without a kernel mapping as the name suggested > (although most of the time they will actually have a kernel mapping..) > > In addition to the conversions of the existing non-coherent DMA users, > I've also added a patch to convert the firewire ohci driver to use > the new dma_alloc_pages API. > > The first patch is queued up for 5.9 in the media tree, but included here > for completeness. > > > A git tree is available here: > > git://git.infradead.org/users/hch/misc.git dma_alloc_pages > > Gitweb: > > http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/dma_alloc_pages > > > Changes since v2: > - fix up the patch reshuffle which wasn't quite correct > - fix up a few commit messages > > Changes since v1: > - rebased on the latests dma-mapping tree, which merged many of the > cleanups > - fix an argument passing typo in 53c700, caught by sparse > - rename a few macro arguments in 53c700 > - pass the right device to the DMA API in the lib82596 drivers > - fix memory ownershiptransfers in sgiseeq > - better document what a page in the direct kernel mapping means > - split into dma_alloc_pages that returns a struct page and is in the > direct mapping vs dma_alloc_noncoherent that can be vmapped > - conver the firewire ohci driver to dma_alloc_pages > > Diffstat: > _______________________________________________ > iommu mailing list > iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu ---end quoted text---