From patchwork Thu May 13 22:31:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12256677 X-Patchwork-Delegate: bhelgaas@google.com 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 31FCEC2B9FC for ; Thu, 13 May 2021 22:32:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8ECC61433 for ; Thu, 13 May 2021 22:32:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233738AbhEMWdk (ORCPT ); Thu, 13 May 2021 18:33:40 -0400 Received: from ale.deltatee.com ([204.191.154.188]:59138 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233656AbhEMWdc (ORCPT ); Thu, 13 May 2021 18:33:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:MIME-Version:References:In-Reply-To: Message-Id:Date:Cc:To:From:content-disposition; bh=IVvn5tn7hJz/M3nGGEc6QXjEojbGjBWgvoIwjwl6ECU=; b=sH+LekVgC3pEDVBU0MY59rGlk4 iog/TLuHrNUSQiugp4e5CPKUzOkW1JGBQZtpY3xnGc0jxKkfvfWcSh1yhSE30LQmRLHAjq5jjnuWm RPu9VlQ8tNRgYaZS1q2VL9ZZo1GPUzKy0aTdVRGmsiPOEaXEAArBeEp3VJ+gsVccwGtCb/1MIH9cY GQDFoExu8Qrc44xn5wMp3fakbTCB7zyQBpVQMi3jmlxmYScAKPMvT7MtTZmB7J87q4+aG6GD2di1k T3MAIH/bWExzTkgvKrTeJvnVg2Adk59FPNv2AKzgtuE0LVC0UgaIo6mwn14zFU6VC9e6ttfvFL479 ERVzYpuQ==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lhJsS-0000nD-Tc; Thu, 13 May 2021 16:32:22 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.92) (envelope-from ) id 1lhJsH-0001TB-Up; Thu, 13 May 2021 16:32:09 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Stephen Bates , Christoph Hellwig , Dan Williams , Jason Gunthorpe , =?utf-8?q?Christian_K=C3=B6nig?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Logan Gunthorpe Date: Thu, 13 May 2021 16:31:56 -0600 Message-Id: <20210513223203.5542-16-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210513223203.5542-1-logang@deltatee.com> References: <20210513223203.5542-1-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-mm@kvack.org, iommu@lists.linux-foundation.org, sbates@raithlin.com, hch@lst.de, jgg@ziepe.ca, christian.koenig@amd.com, jhubbard@nvidia.com, ddutile@redhat.com, willy@infradead.org, daniel.vetter@ffwll.ch, jason@jlekstrand.net, dave.hansen@linux.intel.com, helgaas@kernel.org, dan.j.williams@intel.com, andrzej.jakowski@intel.com, dave.b.minturn@intel.com, jianxin.xiong@intel.com, ira.weiny@intel.com, robin.murphy@arm.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v2 15/22] dma-direct: Support PCI P2PDMA pages in dma-direct map_sg X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Add PCI P2PDMA support for dma_direct_map_sg() so that it can map PCI P2PDMA pages directly without a hack in the callers. This allows for heterogeneous SGLs that contain both P2PDMA and regular pages. A P2PDMA page may have three possible outcomes when being mapped: 1) If the data path between the two devices doesn't go through the root port, then it should be mapped with a PCI bus address 2) If the data path goes through the host bridge, it should be mapped normally, as though it were a CPU physical address 3) It is not possible for the two devices to communicate and thus the mapping operation should fail (and it will return -EREMOTEIO). SGL segments that contain PCI bus addresses are marked with sg_dma_mark_pci_p2pdma() and are ignored when unmapped. Signed-off-by: Logan Gunthorpe --- kernel/dma/direct.c | 44 ++++++++++++++++++++++++++++++++++++++------ 1 file changed, 38 insertions(+), 6 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 803ee9321170..567dac942e89 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -13,6 +13,7 @@ #include #include #include +#include #include "direct.h" /* @@ -381,29 +382,60 @@ void dma_direct_sync_sg_for_cpu(struct device *dev, arch_sync_dma_for_cpu_all(); } +/* + * Unmaps segments, except for ones marked as pci_p2pdma which do not + * require any further action as they contain a bus address. + */ void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl, int nents, enum dma_data_direction dir, unsigned long attrs) { struct scatterlist *sg; int i; - for_each_sg(sgl, sg, nents, i) - dma_direct_unmap_page(dev, sg->dma_address, sg_dma_len(sg), dir, - attrs); + for_each_sg(sgl, sg, nents, i) { + if (sg_is_dma_pci_p2pdma(sg)) { + sg_dma_unmark_pci_p2pdma(sg); + } else { + dma_direct_unmap_page(dev, sg->dma_address, + sg_dma_len(sg), dir, attrs); + } + } } #endif int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, enum dma_data_direction dir, unsigned long attrs) { - int i; + struct pci_p2pdma_map_state p2pdma_state = {}; + enum pci_p2pdma_map_type map; struct scatterlist *sg; + int i, ret; for_each_sg(sgl, sg, nents, i) { + if (is_pci_p2pdma_page(sg_page(sg))) { + map = pci_p2pdma_map_segment(&p2pdma_state, dev, sg); + switch (map) { + case PCI_P2PDMA_MAP_BUS_ADDR: + continue; + case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE: + /* + * Mapping through host bridge should be + * mapped normally, thus we do nothing + * and continue below. + */ + break; + default: + ret = -EREMOTEIO; + goto out_unmap; + } + } + sg->dma_address = dma_direct_map_page(dev, sg_page(sg), sg->offset, sg->length, dir, attrs); - if (sg->dma_address == DMA_MAPPING_ERROR) + if (sg->dma_address == DMA_MAPPING_ERROR) { + ret = -EINVAL; goto out_unmap; + } sg_dma_len(sg) = sg->length; } @@ -411,7 +443,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, out_unmap: dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); - return -EINVAL; + return ret; } dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr,