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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id E2F98CCFA1A for ; Wed, 12 Nov 2025 14:38:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=h4w5bQMB5oBiIu07qOaJ3RLjP1kDllrOpKav/m2ew6k=; b=wumbFP0mPNf2rjGDaorT1rguoo z9kQGrGR0UWAAISkJYCUlwvOvjoNhXDPMzBzMz3Bgl9SDfDvKyNu6/T1xalSlFAK9uPToE5RF+vwx 3Y+zVxdMs1RB3pBCo2p7uI8rLAOuWePLefRjf9PG9gTqk3tD/uCpjsOM0qLYlxmezsq7Tw1qdV8j0 ftZut2DeZ8pjj5k8OF+5DUqm1tjbd8F/gCH165wnIkTBcfyehUaXEKRTJq1OnB+StYbBZzoPGYXlp Eh7mTwJPOXbsUoiGPpeMuG++tOmZHFCZSyLJwM3IphhZV4VlWoX13xyebRIr/XovpfqmJXfZECWtE He/diXDw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vJBzE-00000008wZ9-06sY; Wed, 12 Nov 2025 14:38:16 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vJBzB-00000008wYI-3HpM for linux-nvme@lists.infradead.org; Wed, 12 Nov 2025 14:38:14 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id C790441776; Wed, 12 Nov 2025 14:38:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EDBA7C4CEF8; Wed, 12 Nov 2025 14:38:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762958290; bh=3w+5TRvSRZNdSUCPnulOp1wUZx4xTqD2yLBq2QoKneQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RPV1gENlHnzIHESu9BbF88ylyZanjfn8jyXO2haMRr2VQJBg9aoXf423Z9gkqjY1x tubOVbg5LYUdW8AjO2MGOwFGsccdqID34Hc286+wxwQChN4kXumx+23xJNrSXbE9wz EzmvMq5uLrz/2bMF3NUFbvADRocsT6jmsT+DKLAOUaxPLuEKAn/aQgurCazMx/8JL+ y+6xKFiyH6H52MjrsD0T1m+4Plcnb7a+qGABlPxs1XvuaZfWFhe1SVFYFLkqC2j65M YgcRZFXP4H4LewlG+B+oZZgaQi4QBeVHqRa0XJ1ed+R1K76a1hC6/rUPMKIeCurBhq sl06EsxKqIH9g== Date: Wed, 12 Nov 2025 09:38:07 -0500 From: Keith Busch To: Leon Romanovsky Cc: Jens Axboe , Christoph Hellwig , Sagi Grimberg , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH v3 2/2] block-dma: properly take MMIO path Message-ID: References: <20251027-block-with-mmio-v3-0-ac3370e1f7b7@nvidia.com> <20251027-block-with-mmio-v3-2-ac3370e1f7b7@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251027-block-with-mmio-v3-2-ac3370e1f7b7@nvidia.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251112_063813_860308_A507D0ED X-CRM114-Status: GOOD ( 14.31 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Mon, Oct 27, 2025 at 09:30:21AM +0200, Leon Romanovsky wrote: > @@ -732,13 +746,20 @@ static void nvme_unmap_metadata(struct request *req) > return; > } > > - if (!blk_rq_integrity_dma_unmap(req, dma_dev, &iod->meta_dma_state, > - iod->meta_total_len)) { > + if (iod->flags & IOD_META_P2P) > + map = PCI_P2PDMA_MAP_BUS_ADDR; > + if (iod->flags & IOD_META_MMIO) { > + map = PCI_P2PDMA_MAP_THRU_HOST_BRIDGE; > + attrs |= DMA_ATTR_MMIO; > + } This should be an 'else if' no? > @@ -760,12 +783,20 @@ static void nvme_unmap_data(struct request *req) > return; > } > > - if (!blk_rq_dma_unmap(req, dma_dev, &iod->dma_state, iod->total_len)) { > + if (iod->flags & IOD_DATA_P2P) > + map = PCI_P2PDMA_MAP_BUS_ADDR; > + if (iod->flags & IOD_DATA_MMIO) { > + map = PCI_P2PDMA_MAP_THRU_HOST_BRIDGE; > + attrs |= DMA_ATTR_MMIO; > + } Same here. > @@ -1036,6 +1067,17 @@ static blk_status_t nvme_map_data(struct request *req) > if (!blk_rq_dma_map_iter_start(req, dev->dev, &iod->dma_state, &iter)) > return iter.status; > > + switch (iter.p2pdma.map) { > + case PCI_P2PDMA_MAP_BUS_ADDR: > + iod->flags |= IOD_DATA_P2P; > + break; > + case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: > + iod->flags |= IOD_DATA_MMIO; > + break; > + default: > + return BLK_STS_RESOURCE; > + } Why is it an error if the data isn't a P2PDMA type? > @@ -1058,6 +1100,17 @@ static blk_status_t nvme_pci_setup_meta_sgls(struct request *req) > &iod->meta_dma_state, &iter)) > return iter.status; > > + switch (iter.p2pdma.map) { > + case PCI_P2PDMA_MAP_BUS_ADDR: > + iod->flags |= IOD_META_P2P; > + break; > + case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: > + iod->flags |= IOD_META_MMIO; > + break; > + default: > + return BLK_STS_RESOURCE; > + } Same here.