From: Logan Gunthorpe <logang@deltatee.com> 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" <sbates@raithlin.com>, "Christoph Hellwig" <hch@lst.de>, "Dan Williams" <dan.j.williams@intel.com>, "Jason Gunthorpe" <jgg@ziepe.ca>, "Christian König" <christian.koenig@amd.com>, "John Hubbard" <jhubbard@nvidia.com>, "Don Dutile" <ddutile@redhat.com>, "Matthew Wilcox" <willy@infradead.org>, "Daniel Vetter" <daniel.vetter@ffwll.ch>, "Jakowski Andrzej" <andrzej.jakowski@intel.com>, "Minturn Dave B" <dave.b.minturn@intel.com>, "Jason Ekstrand" <jason@jlekstrand.net>, "Dave Hansen" <dave.hansen@linux.intel.com>, "Xiong Jianxin" <jianxin.xiong@intel.com>, "Bjorn Helgaas" <helgaas@kernel.org>, "Ira Weiny" <ira.weiny@intel.com>, "Robin Murphy" <robin.murphy@arm.com>, "Martin Oliveira" <martin.oliveira@eideticom.com>, "Chaitanya Kulkarni" <ckulkarnilinux@gmail.com>, "Ralph Campbell" <rcampbell@nvidia.com>, "Logan Gunthorpe" <logang@deltatee.com> Subject: [PATCH v6 06/21] dma-direct: support PCI P2PDMA pages in dma-direct map_sg Date: Thu, 7 Apr 2022 09:47:02 -0600 [thread overview] Message-ID: <20220407154717.7695-7-logang@deltatee.com> (raw) In-Reply-To: <20220407154717.7695-1-logang@deltatee.com> 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. P2PDMA mappings are also failed if swiotlb needs to be used on the mapping. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- kernel/dma/direct.c | 43 +++++++++++++++++++++++++++++++++++++------ kernel/dma/direct.h | 8 +++++++- 2 files changed, 44 insertions(+), 7 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 9743c6ccce1a..33b838a3ccb2 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -461,29 +461,60 @@ 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_bus_address(sg)) + sg_dma_unmark_bus_address(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: + /* + * Any P2P mapping that traverses the PCI + * host bridge must be mapped with CPU physical + * address and not PCI bus addresses. This is + * done with dma_direct_map_page() 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 = -EIO; goto out_unmap; + } sg_dma_len(sg) = sg->length; } @@ -491,7 +522,7 @@ 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 -EIO; + return ret; } dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h index 4632b0f4f72e..81b213409ce8 100644 --- a/kernel/dma/direct.h +++ b/kernel/dma/direct.h @@ -8,6 +8,7 @@ #define _KERNEL_DMA_DIRECT_H #include <linux/dma-direct.h> +#include <linux/memremap.h> int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr, size_t size, @@ -87,10 +88,15 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev, phys_addr_t phys = page_to_phys(page) + offset; dma_addr_t dma_addr = phys_to_dma(dev, phys); - if (is_swiotlb_force_bounce(dev)) + if (is_swiotlb_force_bounce(dev)) { + if (is_pci_p2pdma_page(page)) + return DMA_MAPPING_ERROR; return swiotlb_map(dev, phys, size, dir, attrs); + } if (unlikely(!dma_capable(dev, dma_addr, size, true))) { + if (is_pci_p2pdma_page(page)) + return DMA_MAPPING_ERROR; if (swiotlb_force != SWIOTLB_NO_FORCE) return swiotlb_map(dev, phys, size, dir, attrs); -- 2.30.2
WARNING: multiple messages have this Message-ID (diff)
From: Logan Gunthorpe <logang@deltatee.com> 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: "Minturn Dave B" <dave.b.minturn@intel.com>, "Martin Oliveira" <martin.oliveira@eideticom.com>, "Ralph Campbell" <rcampbell@nvidia.com>, "Ira Weiny" <ira.weiny@intel.com>, "John Hubbard" <jhubbard@nvidia.com>, "Dave Hansen" <dave.hansen@linux.intel.com>, "Robin Murphy" <robin.murphy@arm.com>, "Matthew Wilcox" <willy@infradead.org>, "Christian König" <christian.koenig@amd.com>, "Jason Gunthorpe" <jgg@ziepe.ca>, "Logan Gunthorpe" <logang@deltatee.com>, "Chaitanya Kulkarni" <ckulkarnilinux@gmail.com>, "Jason Ekstrand" <jason@jlekstrand.net>, "Daniel Vetter" <daniel.vetter@ffwll.ch>, "Bjorn Helgaas" <helgaas@kernel.org>, "Dan Williams" <dan.j.williams@intel.com>, "Stephen Bates" <sbates@raithlin.com>, "Jakowski Andrzej" <andrzej.jakowski@intel.com>, "Christoph Hellwig" <hch@lst.de>, "Xiong Jianxin" <jianxin.xiong@intel.com> Subject: [PATCH v6 06/21] dma-direct: support PCI P2PDMA pages in dma-direct map_sg Date: Thu, 7 Apr 2022 09:47:02 -0600 [thread overview] Message-ID: <20220407154717.7695-7-logang@deltatee.com> (raw) In-Reply-To: <20220407154717.7695-1-logang@deltatee.com> 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. P2PDMA mappings are also failed if swiotlb needs to be used on the mapping. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- kernel/dma/direct.c | 43 +++++++++++++++++++++++++++++++++++++------ kernel/dma/direct.h | 8 +++++++- 2 files changed, 44 insertions(+), 7 deletions(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 9743c6ccce1a..33b838a3ccb2 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -461,29 +461,60 @@ 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_bus_address(sg)) + sg_dma_unmark_bus_address(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: + /* + * Any P2P mapping that traverses the PCI + * host bridge must be mapped with CPU physical + * address and not PCI bus addresses. This is + * done with dma_direct_map_page() 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 = -EIO; goto out_unmap; + } sg_dma_len(sg) = sg->length; } @@ -491,7 +522,7 @@ 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 -EIO; + return ret; } dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr, diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h index 4632b0f4f72e..81b213409ce8 100644 --- a/kernel/dma/direct.h +++ b/kernel/dma/direct.h @@ -8,6 +8,7 @@ #define _KERNEL_DMA_DIRECT_H #include <linux/dma-direct.h> +#include <linux/memremap.h> int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr, size_t size, @@ -87,10 +88,15 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev, phys_addr_t phys = page_to_phys(page) + offset; dma_addr_t dma_addr = phys_to_dma(dev, phys); - if (is_swiotlb_force_bounce(dev)) + if (is_swiotlb_force_bounce(dev)) { + if (is_pci_p2pdma_page(page)) + return DMA_MAPPING_ERROR; return swiotlb_map(dev, phys, size, dir, attrs); + } if (unlikely(!dma_capable(dev, dma_addr, size, true))) { + if (is_pci_p2pdma_page(page)) + return DMA_MAPPING_ERROR; if (swiotlb_force != SWIOTLB_NO_FORCE) return swiotlb_map(dev, phys, size, dir, attrs); -- 2.30.2 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2022-04-07 17:28 UTC|newest] Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-04-07 15:46 [PATCH v6 00/21] Userspace P2PDMA with O_DIRECT NVMe devices Logan Gunthorpe 2022-04-07 15:46 ` Logan Gunthorpe 2022-04-07 15:46 ` [PATCH v6 01/21] lib/scatterlist: add flag for indicating P2PDMA segments in an SGL Logan Gunthorpe 2022-04-07 15:46 ` Logan Gunthorpe 2022-04-07 15:46 ` [PATCH v6 02/21] PCI/P2PDMA: Attempt to set map_type if it has not been set Logan Gunthorpe 2022-04-07 15:46 ` Logan Gunthorpe 2022-04-07 15:46 ` [PATCH v6 03/21] PCI/P2PDMA: Expose pci_p2pdma_map_type() Logan Gunthorpe 2022-04-07 15:46 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 04/21] PCI/P2PDMA: Introduce helpers for dma_map_sg implementations Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 05/21] dma-mapping: allow EREMOTEIO return code for P2PDMA transfers Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe [this message] 2022-04-07 15:47 ` [PATCH v6 06/21] dma-direct: support PCI P2PDMA pages in dma-direct map_sg Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 07/21] dma-mapping: add flags to dma_map_ops to indicate PCI P2PDMA support Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 08/21] iommu/dma: support PCI P2PDMA pages in dma-iommu map_sg Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 09/21] nvme-pci: check DMA ops when indicating support for PCI P2PDMA Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 10/21] nvme-pci: convert to using dma_map_sgtable() Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 11/21] RDMA/core: introduce ib_dma_pci_p2p_dma_supported() Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 12/21] RDMA/rw: drop pci_p2pdma_[un]map_sg() Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 13/21] PCI/P2PDMA: Remove pci_p2pdma_[un]map_sg() Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 14/21] mm: introduce FOLL_PCI_P2PDMA to gate getting PCI P2PDMA pages Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 15/21] iov_iter: introduce iov_iter_get_pages_[alloc_]flags() Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 16/21] block: add check when merging zone device pages Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 17/21] lib/scatterlist: " Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 18/21] block: set FOLL_PCI_P2PDMA in __bio_iov_iter_get_pages() Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 19/21] block: set FOLL_PCI_P2PDMA in bio_map_user_iov() Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 20/21] PCI/P2PDMA: Introduce pci_mmap_p2pmem() Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-05-27 12:55 ` Jason Gunthorpe 2022-05-27 12:55 ` Jason Gunthorpe 2022-05-27 15:35 ` Logan Gunthorpe 2022-05-27 15:35 ` Logan Gunthorpe 2022-05-27 19:03 ` Jason Gunthorpe 2022-05-27 19:03 ` Jason Gunthorpe 2022-05-27 22:41 ` Logan Gunthorpe 2022-05-27 22:41 ` Logan Gunthorpe 2022-06-02 0:00 ` Jason Gunthorpe 2022-06-02 0:00 ` Jason Gunthorpe 2022-06-02 16:16 ` Logan Gunthorpe 2022-06-02 16:16 ` Logan Gunthorpe 2022-06-02 16:30 ` Jason Gunthorpe 2022-06-02 16:30 ` Jason Gunthorpe 2022-06-02 16:45 ` Logan Gunthorpe 2022-06-02 16:45 ` Logan Gunthorpe 2022-06-02 17:18 ` Jason Gunthorpe 2022-06-02 17:18 ` Jason Gunthorpe 2022-06-02 16:49 ` Logan Gunthorpe 2022-06-02 16:49 ` Logan Gunthorpe 2022-06-02 17:28 ` Jason Gunthorpe 2022-06-02 17:28 ` Jason Gunthorpe 2022-06-02 17:49 ` Logan Gunthorpe 2022-06-02 17:49 ` Logan Gunthorpe 2022-04-07 15:47 ` [PATCH v6 21/21] nvme-pci: allow mmaping the CMB in userspace Logan Gunthorpe 2022-04-07 15:47 ` Logan Gunthorpe 2022-05-16 22:31 ` [PATCH v6 00/21] Userspace P2PDMA with O_DIRECT NVMe devices Chaitanya Kulkarni 2022-05-16 22:31 ` Chaitanya Kulkarni via iommu 2022-05-16 22:35 ` Logan Gunthorpe 2022-05-16 22:35 ` Logan Gunthorpe
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