From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 15E9E33C53F; Wed, 12 Nov 2025 14:38:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762958291; cv=none; b=FxFxJdFWD5odvBGAIFMwsUVus9zp362vlfEdlN0mnNUCvhO+aXteLV+KEYThLHtoGmCu1BMl/cLkeK/9rb42oDeM2KNKs5LqY6rUAxuSLJjiH23LHpDmF7X7bwEJt+vh33XgV2pqQgTv/vU8tRcvIv+MNLFhq/3clf5rwbX2HxY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762958291; c=relaxed/simple; bh=3w+5TRvSRZNdSUCPnulOp1wUZx4xTqD2yLBq2QoKneQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CoLY3tFQdmyul+l7vYpdT8Dn8sBnZPNQGPjqhWo0hC49rf6Y/xWtIV6Qt4jRpRtVtMfaq3PK6iYWfvTnV4RB46MfJvaf5S7MjOYlC/cyFf+6tKHgA0g/yFY8MjB2g0mIYDYbnciaawkHYHdZVBCQAyvtkW8S2k+ecqtvk94P01M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RPV1gENl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RPV1gENl" 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> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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> 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.