From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E365C47427 for ; Tue, 22 Sep 2020 10:56:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0AFB723A5F for ; Tue, 22 Sep 2020 10:56:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0AFB723A5F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=alpha.franken.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1FEC46B00D7; Tue, 22 Sep 2020 06:56:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 18BE46B00CF; Tue, 22 Sep 2020 06:56:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F203B6B00D2; Tue, 22 Sep 2020 06:56:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0178.hostedemail.com [216.40.44.178]) by kanga.kvack.org (Postfix) with ESMTP id CE90E6B00CF for ; Tue, 22 Sep 2020 06:56:17 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 9609D362A for ; Tue, 22 Sep 2020 10:56:17 +0000 (UTC) X-FDA: 77290393194.07.pail57_030eb4c2714d Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id 7413F1803FF14 for ; Tue, 22 Sep 2020 10:56:17 +0000 (UTC) X-HE-Tag: pail57_030eb4c2714d X-Filterd-Recvd-Size: 3050 Received: from elvis.franken.de (elvis.franken.de [193.175.24.41]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Tue, 22 Sep 2020 10:56:16 +0000 (UTC) Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1kKfxr-000822-01; Tue, 22 Sep 2020 12:56:03 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id B061AC0FFF; Tue, 22 Sep 2020 10:49:34 +0200 (CEST) Date: Tue, 22 Sep 2020 10:49:34 +0200 From: Thomas Bogendoerfer To: Christoph Hellwig Cc: Mauro Carvalho Chehab , "James E.J. Bottomley" , Joonyoung Shim , Seung-Woo Kim , Ben Skeggs , Marek Szyprowski , Tomasz Figa , Matt Porter , iommu@lists.linux-foundation.org, Stefan Richter , linux1394-devel@lists.sourceforge.net, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, netdev@vger.kernel.org, linux-scsi@vger.kernel.org, linux-mm@kvack.org, alsa-devel@alsa-project.org Subject: Re: [PATCH 07/18] 53c700: improve non-coherent DMA handling Message-ID: <20200922084934.GB8477@alpha.franken.de> References: <20200915155122.1768241-1-hch@lst.de> <20200915155122.1768241-8-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200915155122.1768241-8-hch@lst.de> User-Agent: Mutt/1.5.23 (2014-03-12) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Sep 15, 2020 at 05:51:11PM +0200, Christoph Hellwig wrote: > Switch the 53c700 driver to only use non-coherent descriptor memory if it > really has to because dma_alloc_coherent fails. This doesn't matter for > any of the platforms it runs on currently, but that will change soon. > > To help with this two new helpers to transfer ownership to and from the > device are added that abstract the syncing of the non-coherent memory. > The two current bidirectional cases are mapped to transfers to the > device, as that appears to what they are used for. Note that for parisc, > which is the only architecture this driver needs to use non-coherent > memory on, the direction argument of dma_cache_sync is ignored, so this > will not change behavior in any way. > > Signed-off-by: Christoph Hellwig > --- > drivers/scsi/53c700.c | 113 +++++++++++++++++++++++------------------- > drivers/scsi/53c700.h | 17 ++++--- > 2 files changed, 72 insertions(+), 58 deletions(-) Tested-by: Thomas Bogendoerfer -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]