From patchwork Mon Jul 22 23:08:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 11053659 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 BA9D1186E for ; Mon, 22 Jul 2019 23:10:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A9D6D26E96 for ; Mon, 22 Jul 2019 23:10:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9E1AE274D0; Mon, 22 Jul 2019 23:10:17 +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 232B9271CB for ; Mon, 22 Jul 2019 23:10:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733174AbfGVXJM (ORCPT ); Mon, 22 Jul 2019 19:09:12 -0400 Received: from ale.deltatee.com ([207.54.116.67]:40254 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728191AbfGVXJM (ORCPT ); Mon, 22 Jul 2019 19:09:12 -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 1hphQb-0002k9-Dj; Mon, 22 Jul 2019 17:09:11 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.89) (envelope-from ) id 1hphQX-0001RH-V5; Mon, 22 Jul 2019 17:09:06 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org Cc: Bjorn Helgaas , Christoph Hellwig , Christian Koenig , Jason Gunthorpe , Sagi Grimberg , Keith Busch , Jens Axboe , Dan Williams , Eric Pilmore , Stephen Bates , Logan Gunthorpe Date: Mon, 22 Jul 2019 17:08:59 -0600 Message-Id: <20190722230859.5436-15-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190722230859.5436-1-logang@deltatee.com> References: <20190722230859.5436-1-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-pci@vger.kernel.org, linux-rdma@vger.kernel.org, bhelgaas@google.com, hch@lst.de, Christian.Koenig@amd.com, jgg@mellanox.com, sagi@grimberg.me, kbusch@kernel.org, axboe@fb.com, dan.j.williams@intel.com, epilmore@gigaio.com, sbates@raithlin.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH 14/14] PCI/P2PDMA: Introduce pci_p2pdma_[un]map_resource() 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-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP pci_p2pdma_[un]map_resource() can be used to map a resource given it's physical address and the backing pci_dev. The functions will call dma_[un]map_resource() when appropriate. This is for demonstration purposes only as there are no users of this function at this time. Thus, this patch should not be merged at this time. Signed-off-by: Logan Gunthorpe Reviewed-by: Christian König --- drivers/pci/p2pdma.c | 85 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index baf476039396..20c834cfd2d3 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -874,6 +874,91 @@ void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL_GPL(pci_p2pdma_unmap_sg_attrs); +static pci_bus_addr_t pci_p2pdma_phys_to_bus(struct pci_dev *dev, + phys_addr_t start, size_t size) +{ + struct pci_host_bridge *bridge = pci_find_host_bridge(dev->bus); + phys_addr_t end = start + size; + struct resource_entry *window; + + resource_list_for_each_entry(window, &bridge->windows) { + if (window->res->start <= start && window->res->end >= end) + return start - window->offset; + } + + return DMA_MAPPING_ERROR; +} +EXPORT_SYMBOL_GPL(pci_p2pdma_phys_to_bus); + +/** + * pci_p2pdma_map_resource - map a PCI peer-to-peer physical address for DMA + * @provider: pci device that provides the memory backed by phys_addr + * @dma_dev: device doing the DMA request + * @phys_addr: physical address of the memory to map + * @size: size of the memory to map + * @dir: DMA direction + * @attrs: dma attributes passed to dma_map_resource() (if called) + * + * Maps a BAR physical address for programming a DMA engine. + * + * Returns the dma_addr_t to map or DMA_MAPPING_ERROR on failure + */ +dma_addr_t pci_p2pdma_map_resource(struct pci_dev *provider, + struct device *dma_dev, phys_addr_t phys_addr, size_t size, + enum dma_data_direction dir, unsigned long attrs) +{ + struct pci_dev *client; + int dist; + + client = find_parent_pci_dev(dma_dev); + if (!client) + return DMA_MAPPING_ERROR; + + dist = upstream_bridge_distance(provider, client, NULL); + if (dist & P2PDMA_NOT_SUPPORTED) + return DMA_MAPPING_ERROR; + + if (dist & P2PDMA_THRU_HOST_BRIDGE) + return dma_map_resource(dma_dev, phys_addr, size, dir, attrs); + else + return pci_p2pdma_phys_to_bus(provider, phys_addr, size); +} +EXPORT_SYMBOL_GPL(pci_p2pdma_map_resource); + +/** + * pci_p2pdma_unmap_resource - unmap a resource mapped with + * pci_p2pdma_map_resource() + * @provider: pci device that provides the memory backed by phys_addr + * @dma_dev: device doing the DMA request + * @addr: dma address returned by pci_p2pdma_unmap_resource() + * @size: size of the memory to map + * @dir: DMA direction + * @attrs: dma attributes passed to dma_unmap_resource() (if called) + * + * Maps a BAR physical address for programming a DMA engine. + * + * Returns the dma_addr_t to map or DMA_MAPPING_ERROR on failure + */ +void pci_p2pdma_unmap_resource(struct pci_dev *provider, + struct device *dma_dev, dma_addr_t addr, size_t size, + enum dma_data_direction dir, unsigned long attrs) +{ + struct pci_dev *client; + int dist; + + client = find_parent_pci_dev(dma_dev); + if (!client) + return; + + dist = upstream_bridge_distance(provider, client, NULL); + if (dist & P2PDMA_NOT_SUPPORTED) + return; + + if (dist & P2PDMA_THRU_HOST_BRIDGE) + dma_unmap_resource(dma_dev, addr, size, dir, attrs); +} +EXPORT_SYMBOL_GPL(pci_p2pdma_unmap_resource); + /** * pci_p2pdma_enable_store - parse a configfs/sysfs attribute store * to enable p2pdma