From patchwork Thu May 13 22:31:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12256681 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 56901C2B9FF 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 287D76148E for ; Thu, 13 May 2021 22:32:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233735AbhEMWdk (ORCPT ); Thu, 13 May 2021 18:33:40 -0400 Received: from ale.deltatee.com ([204.191.154.188]:59148 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233657AbhEMWdc (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=6u9ILVRKlmqudAt9Un+7r9dFNUtTIxAGQYUmPLCOvYA=; b=pe5Fdee9kavi5iFg2CLlP1bXFi HU3RX2gpRFQZ9fmvX22kRlQ9tmoW1IQw9r+DGQ3T3QdxtHl3b/VIO94fKdjopL37vqgg7Zzjftxmp jHgPUcB0KTR9a9MvX0FNQxNUzwfyTStes45pWzv97i1orQZqpuIMdSY+cOI6Ig8VJvZCOv6tDm5LD hMZXY0cQDmv3jkeOuUICge6tIqsC7jCs6gsGnrMMIXgbb/n5ct/WAVE6Ir4yPw5uO8qGdXCrNaoi6 BDfCh+SFrIw/vLTFiSiOBO9e0V4S9GH47DCSSlWyDULHacflmdBU43SvbEookKvEvFgmAg6wIqjMD 1AWe8ueg==; 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 1lhJsT-0000nF-8J; 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-0001T8-PQ; 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 16:31:55 -0600 Message-Id: <20210513223203.5542-15-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 14/22] PCI/P2PDMA: Introduce helpers for dma_map_sg implementations 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_map_segment() as a helper for simple dma_map_sg() implementations. It takes an scatterlist segment that must point to a pci_p2pdma struct page and will map it if the mapping requires a bus address. The return value indicates whether the mapping required a bus address or whether the caller still needs to map the segment normally. If the segment should not be mapped, -EREMOTEIO is returned. This helper uses a state structure to track the changes to the pgmap across calls and avoid needing to lookup into the xarray for every page. Also add pci_p2pdma_map_bus_segment() which is useful for IOMMU dma_map_sg() implementations where the sg segment containing the page differs from the sg segment containing the DMA address. Signed-off-by: Logan Gunthorpe --- drivers/pci/p2pdma.c | 59 ++++++++++++++++++++++++++++++++++++++ include/linux/pci-p2pdma.h | 21 ++++++++++++++ 2 files changed, 80 insertions(+) diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 0568604fd8b4..b0d779aeade9 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -938,6 +938,65 @@ void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL_GPL(pci_p2pdma_unmap_sg_attrs); +/** + * pci_p2pdma_map_segment - map an sg segment determining the mapping type + * @state: State structure that should be declared outside of the for_each_sg() + * loop and initialized to zero. + * @dev: DMA device that's doing the mapping operation + * @sg: scatterlist segment to map + * + * This is a helper to be used by non-iommu dma_map_sg() implementations where + * the sg segment is the same for the page_link and the dma_address. + * + * Attempt to map a single segment in an SGL with the PCI bus address. + * The segment must point to a PCI P2PDMA page and thus must be + * wrapped in a is_pci_p2pdma_page(sg_page(sg)) check. + * + * Returns the type of mapping used and maps the page if the type is + * PCI_P2PDMA_MAP_BUS_ADDR. + */ +enum pci_p2pdma_map_type +pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev, + struct scatterlist *sg) +{ + if (state->pgmap != sg_page(sg)->pgmap) { + state->pgmap = sg_page(sg)->pgmap; + state->map = pci_p2pdma_map_type(state->pgmap, dev); + state->bus_off = to_p2p_pgmap(state->pgmap)->bus_offset; + } + + if (state->map == PCI_P2PDMA_MAP_BUS_ADDR) { + sg->dma_address = sg_phys(sg) + state->bus_off; + sg_dma_len(sg) = sg->length; + sg_dma_mark_pci_p2pdma(sg); + } + + return state->map; +} + +/** + * pci_p2pdma_map_bus_segment - map an sg segment pre determined to + * be mapped with PCI_P2PDMA_MAP_BUS_ADDR + * @pg_sg: scatterlist segment with the page to map + * @dma_sg: scatterlist segment to assign a dma address to + * + * This is a helper for iommu dma_map_sg() implementations when the + * segment for the dma address differs from the segment containing the + * source page. + * + * pci_p2pdma_map_type() must have already been called on the pg_sg and + * returned PCI_P2PDMA_MAP_BUS_ADDR. + */ +void pci_p2pdma_map_bus_segment(struct scatterlist *pg_sg, + struct scatterlist *dma_sg) +{ + struct pci_p2pdma_pagemap *pgmap = to_p2p_pgmap(sg_page(pg_sg)->pgmap); + + dma_sg->dma_address = sg_phys(pg_sg) + pgmap->bus_offset; + sg_dma_len(dma_sg) = pg_sg->length; + sg_dma_mark_pci_p2pdma(dma_sg); +} + /** * pci_p2pdma_enable_store - parse a configfs/sysfs attribute store * to enable p2pdma diff --git a/include/linux/pci-p2pdma.h b/include/linux/pci-p2pdma.h index caac2d023f8f..e5a8d5bc0f51 100644 --- a/include/linux/pci-p2pdma.h +++ b/include/linux/pci-p2pdma.h @@ -13,6 +13,12 @@ #include +struct pci_p2pdma_map_state { + struct dev_pagemap *pgmap; + int map; + u64 bus_off; +}; + struct block_device; struct scatterlist; @@ -70,6 +76,11 @@ int pci_p2pdma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); +enum pci_p2pdma_map_type +pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev, + struct scatterlist *sg); +void pci_p2pdma_map_bus_segment(struct scatterlist *pg_sg, + struct scatterlist *dma_sg); int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev, bool *use_p2pdma); ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev, @@ -135,6 +146,16 @@ static inline void pci_p2pdma_unmap_sg_attrs(struct device *dev, unsigned long attrs) { } +static inline enum pci_p2pdma_map_type +pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev, + struct scatterlist *sg) +{ + return PCI_P2PDMA_MAP_NOT_SUPPORTED; +} +static inline void pci_p2pdma_map_bus_segment(struct scatterlist *pg_sg, + struct scatterlist *dma_sg) +{ +} static inline int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev, bool *use_p2pdma) {