From patchwork Thu Jun 20 16:12:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 11007351 X-Patchwork-Delegate: bhelgaas@google.com 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 C03B9112C for ; Thu, 20 Jun 2019 16:15:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B23DB282E8 for ; Thu, 20 Jun 2019 16:15:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A66BF2874F; Thu, 20 Jun 2019 16:15:08 +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=-7.9 required=2.0 tests=BAYES_00,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 4FB87282E8 for ; Thu, 20 Jun 2019 16:15:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732507AbfFTQPH (ORCPT ); Thu, 20 Jun 2019 12:15:07 -0400 Received: from ale.deltatee.com ([207.54.116.67]:59352 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726979AbfFTQMv (ORCPT ); Thu, 20 Jun 2019 12:12:51 -0400 Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hdzg6-00046L-69; Thu, 20 Jun 2019 10:12:50 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.89) (envelope-from ) id 1hdzg4-0005w5-65; Thu, 20 Jun 2019 10:12:44 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, linux-rdma@vger.kernel.org Cc: Jens Axboe , Christoph Hellwig , Bjorn Helgaas , Dan Williams , Sagi Grimberg , Keith Busch , Jason Gunthorpe , Stephen Bates , Logan Gunthorpe Date: Thu, 20 Jun 2019 10:12:16 -0600 Message-Id: <20190620161240.22738-5-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190620161240.22738-1-logang@deltatee.com> References: <20190620161240.22738-1-logang@deltatee.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-rdma@vger.kernel.org, axboe@kernel.dk, hch@lst.de, bhelgaas@google.com, dan.j.williams@intel.com, sagi@grimberg.me, kbusch@kernel.org, jgg@ziepe.ca, sbates@raithlin.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [RFC PATCH 04/28] block: Never bounce dma-direct bios X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP It is expected the creator of the dma-direct bio will ensure the target device can access the DMA address it's creating bios for. It's also not possible to bounce a dma-direct bio seeing the block layer doesn't have any way to access the underlying data behind the DMA address. Thus, never bounce dma-direct bios. Signed-off-by: Logan Gunthorpe --- block/bounce.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/block/bounce.c b/block/bounce.c index f8ed677a1bf7..17e020a40cca 100644 --- a/block/bounce.c +++ b/block/bounce.c @@ -367,6 +367,14 @@ void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) if (!bio_has_data(*bio_orig)) return; + /* + * For DMA direct bios, Upper layers are expected to ensure + * the device in question can access the DMA addresses. So + * it never makes sense to bounce a DMA direct bio. + */ + if (bio_is_dma_direct(*bio_orig)) + return; + /* * for non-isa bounce case, just check if the bounce pfn is equal * to or bigger than the highest pfn in the system -- in that case,