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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 2B0A2C10F13 for ; Thu, 11 Apr 2019 14:34:54 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ECC8C206BA for ; Thu, 11 Apr 2019 14:34:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="EHZ1HgiZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECC8C206BA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Ye++jJ3TCjoFxIHvqc1Xci4AwfEA0Tdbd6I9K2WZSec=; b=EHZ1HgiZ5PcsPY et5rYRTZfgnS6lhpxwMgSJFsdcUwpQBpQonQar/v0DvS+/z48wzpeghEuD0qgNKe/H0zoTzwpnm+7 p2iXJ218ZWZkpkv5x5+y0CIH0Xxj7ZrnOfoPzZMtsDkmo3mfFEdBU6vATbmps/a9sGJV9iGM1ZvcX 7QsBvmEcrIU0iCtrXuRFxltDcBqqqr9A556iptZbVxtPVKIRaKrTnGhfyNbWvjffU69zE6uwm/PAu y5BYPQm0Nh6vT2bUgHyAJXEPRvGYQ0Z6FgQ8sFfU2vKa/+/WCvfQ1LGHrGIrSlGEkPTQR8sIJBQmb v2XVSsiGmCZisvEler3A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEamx-0001c6-5P; Thu, 11 Apr 2019 14:34:51 +0000 Received: from verein.lst.de ([213.95.11.211] helo=newverein.lst.de) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEamt-0001b7-9M for linux-arm-kernel@lists.infradead.org; Thu, 11 Apr 2019 14:34:49 +0000 Received: by newverein.lst.de (Postfix, from userid 2407) id 150ED68AFE; Thu, 11 Apr 2019 16:34:31 +0200 (CEST) Date: Thu, 11 Apr 2019 16:34:30 +0200 From: Christoph Hellwig To: Ulf Hansson Subject: Re: [PATCH 1/2] mmc: let the dma map ops handle bouncing Message-ID: <20190411143430.GA17371@lst.de> References: <20190411070948.29564-1-hch@lst.de> <20190411070948.29564-2-hch@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190411_073447_474795_E14B4E0C X-CRM114-Status: GOOD ( 12.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-mmc@vger.kernel.org" , Linux Kernel Mailing List , Russell King , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Christoph Hellwig , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Apr 11, 2019 at 11:00:56AM +0200, Ulf Hansson wrote: > > blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue); > > if (mmc_can_erase(card)) > > mmc_queue_setup_discard(mq->queue, card); > > > > - blk_queue_bounce_limit(mq->queue, limit); > > + if (!mmc_dev(host)->dma_mask || !*mmc_dev(host)->dma_mask) > > + blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH); > > So this means we are not going to set a bounce limit for the queue, in > case we have a dma mask. > > Why isn't that needed no more? Whats has changed? On most architectures it was never needed, the major hold out was x86-32 with PAE. In general the dma_mask tells the DMA API layer what is supported, and if the physical addressing doesn't support that it has to use bounce buffering like swiotlb (or dmabounce on arm32). A couple month ago I finally fixes x86-32 to also properly set up swiotlb, and remove the block layerer bounce buffering that wasn't for highmem (which is about having a kernel mapping, not addressing), and ISA DMA (which is not handled like everything else, but we'll get there). But for some reason I missed mmc back then, so mmc right now is the only remaining user of address based block layer bouncing. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel