From patchwork Thu Mar 21 23:10:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10864551 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A6EB86C2 for ; Thu, 21 Mar 2019 23:12:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8F8E12A541 for ; Thu, 21 Mar 2019 23:12:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 842312A543; Thu, 21 Mar 2019 23:12:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 090872A541 for ; Thu, 21 Mar 2019 23:12:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727399AbfCUXMK (ORCPT ); Thu, 21 Mar 2019 19:12:10 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:51688 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727000AbfCUXMK (ORCPT ); Thu, 21 Mar 2019 19:12:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Ig7GqXoHZPgdkj33sZ9nPGcAdlSXMBhgaTI2SqAfns8=; b=SXfMDwb9dFFroII+dL6S2E+XuV WGo950S7RLAyAtTR4cZUh+iV8lfGTHUAIIjfzlYVaHijU5YsPD89AggHLzH+8arjtAIX+aT+FmH8K pd2L+aR1IIhavJC8+zeToS7Htupt/TDdoBTiLqE7G7JN7RU3g7/zqcjeze/l/B6PtZINHgLs0Csjy SUiVT/UJ7MSoTq0EBoCtLPIc0PQrcvKyO1CyQ/GWbYnaWRk39XAnNgXieu/YOPGfHbjbuiqdd6VIL Fg6yt2bsdm2XYyQEckXxgcXNlVmrVquJ6SRv2E5v8AdCnN4lzukTfEwXtLJQxImb5qo69L4SjW0Wg MCIVXPZg==; Received: from [199.255.44.128] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1h76r0-0003qk-Ad; Thu, 21 Mar 2019 23:12:06 +0000 From: Christoph Hellwig To: Jens Axboe , Keith Busch , Sagi Grimberg Cc: linux-nvme@lists.infradead.org, linux-block@vger.kernel.org Subject: [PATCH 13/15] nvme-pci: optimize mapping of small single segment requests Date: Thu, 21 Mar 2019 16:10:35 -0700 Message-Id: <20190321231037.25104-14-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190321231037.25104-1-hch@lst.de> References: <20190321231037.25104-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If a request is single segment and fits into one or two PRP entries we do not have to create a scatterlist for it, but can just map the bio_vec directly. Signed-off-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni --- drivers/nvme/host/pci.c | 45 ++++++++++++++++++++++++++++++++++++----- 1 file changed, 40 insertions(+), 5 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index c6047935e825..47fc4d653961 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -221,6 +221,7 @@ struct nvme_iod { int npages; /* In the PRP list. 0 means small pool in use */ int nents; /* Used in scatterlist */ dma_addr_t first_dma; + unsigned int dma_len; /* length of single DMA segment mapping */ dma_addr_t meta_dma; struct scatterlist *sg; }; @@ -576,13 +577,18 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct request *req) dma_addr_t dma_addr = iod->first_dma, next_dma_addr; int i; - if (iod->nents) { - /* P2PDMA requests do not need to be unmapped */ - if (!is_pci_p2pdma_page(sg_page(iod->sg))) - dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir); - + if (iod->dma_len) { + dma_unmap_page(dev->dev, dma_addr, iod->dma_len, dma_dir); + return; } + WARN_ON_ONCE(!iod->nents); + + /* P2PDMA requests do not need to be unmapped */ + if (!is_pci_p2pdma_page(sg_page(iod->sg))) + dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req)); + + if (iod->npages == 0) dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0], dma_addr); @@ -795,6 +801,24 @@ static blk_status_t nvme_pci_setup_sgls(struct nvme_dev *dev, return BLK_STS_OK; } +static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev, + struct request *req, struct nvme_rw_command *cmnd, + struct bio_vec *bv) +{ + struct nvme_iod *iod = blk_mq_rq_to_pdu(req); + unsigned int first_prp_len = dev->ctrl.page_size - bv->bv_offset; + + iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0); + if (dma_mapping_error(dev->dev, iod->first_dma)) + return BLK_STS_RESOURCE; + iod->dma_len = bv->bv_len; + + cmnd->dptr.prp1 = cpu_to_le64(iod->first_dma); + if (bv->bv_len > first_prp_len) + cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma + first_prp_len); + return 0; +} + static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, struct nvme_command *cmnd) { @@ -805,6 +829,17 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, blk_status_t ret = BLK_STS_IOERR; int nr_mapped; + if (blk_rq_nr_phys_segments(req) == 1) { + struct bio_vec bv = req_bvec(req); + + if (!is_pci_p2pdma_page(bv.bv_page)) { + if (bv.bv_offset + bv.bv_len <= dev->ctrl.page_size * 2) + return nvme_setup_prp_simple(dev, req, + &cmnd->rw, &bv); + } + } + + iod->dma_len = 0; iod->sg = mempool_alloc(dev->iod_mempool, GFP_ATOMIC); if (!iod->sg) return BLK_STS_RESOURCE;