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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 D92FBC43613 for ; Mon, 24 Jun 2019 06:24:47 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 BBBE321670 for ; Mon, 24 Jun 2019 06:24:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BBBE321670 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 8095DC21; Mon, 24 Jun 2019 06:24:47 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 4FC60BA9 for ; Mon, 24 Jun 2019 06:24:46 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from newverein.lst.de (verein.lst.de [213.95.11.211]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id D3149710 for ; Mon, 24 Jun 2019 06:24:45 +0000 (UTC) Received: by newverein.lst.de (Postfix, from userid 2407) id 19E9568AFE; Mon, 24 Jun 2019 08:24:15 +0200 (CEST) Date: Mon, 24 Jun 2019 08:24:14 +0200 From: Christoph Hellwig To: Yoshihiro Shimoda Subject: Re: [RFC PATCH v7 5/5] mmc: queue: Use bigger segments if DMA MAP layer can merge the segments Message-ID: <20190624062414.GD2989@lst.de> References: <1561020610-953-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> <1561020610-953-6-git-send-email-yoshihiro.shimoda.uh@renesas.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1561020610-953-6-git-send-email-yoshihiro.shimoda.uh@renesas.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: axboe@kernel.dk, linux-renesas-soc@vger.kernel.org, ulf.hansson@linaro.org, linux-mmc@vger.kernel.org, linux-block@vger.kernel.org, wsa+renesas@sang-engineering.com, iommu@lists.linux-foundation.org, robin.murphy@arm.com, hch@lst.de X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Thu, Jun 20, 2019 at 05:50:10PM +0900, Yoshihiro Shimoda wrote: > When the max_segs of a mmc host is smaller than 512, the mmc > subsystem tries to use 512 segments if DMA MAP layer can merge > the segments, and then the mmc subsystem exposes such information > to the block layer by using blk_queue_can_use_dma_map_merging(). > > Signed-off-by: Yoshihiro Shimoda > --- > drivers/mmc/core/queue.c | 35 ++++++++++++++++++++++++++++++++--- > include/linux/mmc/host.h | 1 + > 2 files changed, 33 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c > index 92900a0..ab0ecc6 100644 > --- a/drivers/mmc/core/queue.c > +++ b/drivers/mmc/core/queue.c > @@ -24,6 +24,8 @@ > #include "card.h" > #include "host.h" > > +#define MMC_DMA_MAP_MERGE_SEGMENTS 512 > + > static inline bool mmc_cqe_dcmd_busy(struct mmc_queue *mq) > { > /* Allow only 1 DCMD at a time */ > @@ -196,6 +198,12 @@ static void mmc_queue_setup_discard(struct request_queue *q, > blk_queue_flag_set(QUEUE_FLAG_SECERASE, q); > } > > +static unsigned int mmc_get_max_segments(struct mmc_host *host) > +{ > + return host->can_dma_map_merge ? MMC_DMA_MAP_MERGE_SEGMENTS : > + host->max_segs; I personally don't like superflous use of ? : if an if would be more obvious: if (host->can_dma_map_merge) return MMC_DMA_MAP_MERGE_SEGMENTS; return host->max_segs; but that is really just a nitpick and for the mmc maintainer to decide. Otherwise looks good: Reviewed-by: Christoph Hellwig _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu