From mboxrd@z Thu Jan 1 00:00:00 1970 From: Logan Gunthorpe Subject: [PATCH 03/12] pci-p2p: Add PCI p2pmem dma mappings to adjust the bus offset Date: Thu, 4 Jan 2018 12:01:28 -0700 Message-ID: <20180104190137.7654-4-logang@deltatee.com> References: <20180104190137.7654-1-logang@deltatee.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180104190137.7654-1-logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Jens Axboe , Benjamin Herrenschmidt , Keith Busch , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jason Gunthorpe , Bjorn Helgaas , Max Gurtovoy , Christoph Hellwig List-Id: linux-rdma@vger.kernel.org The DMA address used when mapping PCI P2P memory must be the PCI bus address. Thus, introduce pci_p2pmem_[un]map_sg() to map the correct addresses when using P2P memory. For this, we assume that an SGL passed to these functions contain all p2p memory or no p2p memory. Signed-off-by: Logan Gunthorpe --- drivers/pci/p2p.c | 43 +++++++++++++++++++++++++++++++++++++++++++ include/linux/memremap.h | 1 + include/linux/pci-p2p.h | 9 +++++++++ 3 files changed, 53 insertions(+) diff --git a/drivers/pci/p2p.c b/drivers/pci/p2p.c index 03330c7b5e6d..87cec87b02e3 100644 --- a/drivers/pci/p2p.c +++ b/drivers/pci/p2p.c @@ -184,6 +184,8 @@ int pci_p2pmem_add_resource(struct pci_dev *pdev, int bar, size_t size, pgmap->res.end = pgmap->res.start + size - 1; pgmap->ref = &pdev->p2p->devmap_ref; pgmap->type = MEMORY_DEVICE_PCI_P2P; + pgmap->pci_p2p_bus_offset = pci_bus_address(pdev, bar) - + pci_resource_start(pdev, bar); addr = devm_memremap_pages(&pdev->dev, pgmap); if (IS_ERR(addr)) @@ -598,3 +600,44 @@ void pci_p2pmem_publish(struct pci_dev *pdev, bool publish) pdev->p2p->published = publish; } EXPORT_SYMBOL_GPL(pci_p2pmem_publish); + +/* + * pci_p2pmem_map_sg - map a pci p2p sg for dma + * @sg:scatter list to map + * @nents:elements in the scatter list + * + * Returns the number of sgls mapped + */ +int pci_p2pmem_map_sg(struct scatterlist *sg, int nents) +{ + struct dev_pagemap *pgmap; + struct scatterlist *s; + phys_addr_t paddr; + int i; + + for_each_sg(sg, s, nents, i) { + pgmap = sg_page(s)->pgmap; + paddr = sg_phys(s); + + s->dma_address = paddr - pgmap->pci_p2p_bus_offset; + sg_dma_len(s) = s->length; + } + + return nents; +} +EXPORT_SYMBOL_GPL(pci_p2pmem_map_sg); + +/** + * pci_p2pmem_unmap_sg - unmap a pci p2p sg for dma + * @sg:scatter list to map + * @nents:elements in the scatter list + */ +void pci_p2pmem_unmap_sg(struct scatterlist *sg, int nents) +{ + struct scatterlist *s; + int i; + + for_each_sg(sg, s, nents, i) + dma_mark_clean(phys_to_virt(sg_phys(s)), sg_dma_len(s)); +} +EXPORT_SYMBOL_GPL(pci_p2pmem_unmap_sg); diff --git a/include/linux/memremap.h b/include/linux/memremap.h index c17a6d167d48..a792f87b9dc3 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -125,6 +125,7 @@ struct dev_pagemap { struct device *dev; void *data; enum memory_type type; + u64 pci_p2p_bus_offset; }; #ifdef CONFIG_ZONE_DEVICE diff --git a/include/linux/pci-p2p.h b/include/linux/pci-p2p.h index f811c97a5886..154c39905fc9 100644 --- a/include/linux/pci-p2p.h +++ b/include/linux/pci-p2p.h @@ -34,6 +34,8 @@ int pci_p2pmem_alloc_sgl(struct pci_dev *pdev, struct scatterlist **sgl, void pci_p2pmem_free_sgl(struct pci_dev *pdev, struct scatterlist *sgl, unsigned int nents); void pci_p2pmem_publish(struct pci_dev *pdev, bool publish); +int pci_p2pmem_map_sg(struct scatterlist *sg, int nents); +void pci_p2pmem_unmap_sg(struct scatterlist *sg, int nents); #else /* CONFIG_PCI_P2P */ static inline int pci_p2pmem_add_resource(struct pci_dev *pdev, int bar, size_t size, u64 offset) @@ -81,5 +83,12 @@ static inline void pci_p2pmem_free_sgl(struct pci_dev *pdev, static inline void pci_p2pmem_publish(struct pci_dev *pdev, bool publish) { } +static inline int pci_p2pmem_map_sg(struct scatterlist *sg, int nents) +{ + return -ENODEV; +} +static inline void pci_p2pmem_unmap_sg(struct scatterlist *sg, int nents) +{ +} #endif /* CONFIG_PCI_P2P */ #endif /* _LINUX_PCI_P2P_H */ -- 2.11.0