| Message ID | 20180228234006.21093-4-logang@deltatee.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Wed, Feb 28, 2018 at 04:39:59PM -0700, Logan Gunthorpe wrote: > 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 <logang@deltatee.com> > --- > drivers/pci/p2pdma.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/memremap.h | 1 + > include/linux/pci-p2pdma.h | 13 ++++++++++++ > 3 files changed, 65 insertions(+) > > diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c > index a57df78f6a32..4e1c81f64b29 100644 > --- a/drivers/pci/p2pdma.c > +++ b/drivers/pci/p2pdma.c > @@ -188,6 +188,8 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size, > pgmap->res.flags = pci_resource_flags(pdev, bar); > pgmap->ref = &pdev->p2pdma->devmap_ref; > pgmap->type = MEMORY_DEVICE_PCI_P2PDMA; > + pgmap->pci_p2pdma_bus_offset = pci_bus_address(pdev, bar) - > + pci_resource_start(pdev, bar); > > addr = devm_memremap_pages(&pdev->dev, pgmap); > if (IS_ERR(addr)) > @@ -616,3 +618,52 @@ void pci_p2pmem_publish(struct pci_dev *pdev, bool publish) > pdev->p2pdma->published = publish; > } > EXPORT_SYMBOL_GPL(pci_p2pmem_publish); > + > +/* > + * pci_p2pdma_map_sg - map a PCI peer-to-peer sg for DMA > + * @dev: device doing the DMA request > + * @sg: scatter list to map > + * @nents: elements in the scatterlist > + * @dir: DMA direction Can you fix these so the descriptions all have a single space after the "@dev:", which seems to be the existing convention in this file? The indentation looks pretty random now. > + * > + * Returns the number of SG entries mapped > + */ > +int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents, > + enum dma_data_direction dir) Same question as before about why the mixture of "pci_*" interfaces that take "struct device *" parameters. > +{ > + struct dev_pagemap *pgmap; > + struct scatterlist *s; > + phys_addr_t paddr; > + int i; > + > + /* > + * p2pdma mappings are not compatible with devices that use > + * dma_virt_ops. > + */ > + if (IS_ENABLED(CONFIG_DMA_VIRT_OPS) && dev->dma_ops == &dma_virt_ops) > + return 0; > + > + for_each_sg(sg, s, nents, i) { > + pgmap = sg_page(s)->pgmap; > + paddr = sg_phys(s); > + > + s->dma_address = paddr - pgmap->pci_p2pdma_bus_offset; > + sg_dma_len(s) = s->length; > + } > + > + return nents; > +} > +EXPORT_SYMBOL_GPL(pci_p2pdma_map_sg); > + > +/** > + * pci_p2pdma_unmap_sg - unmap a PCI peer-to-peer sg for DMA > + * @dev: device doing the DMA request > + * @sg: scatter list to map > + * @nents: elements in the scatterlist > + * @dir: DMA direction Same whitespace comment as above. > + */ > +void pci_p2pdma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, > + enum dma_data_direction dir) > +{ > +} > +EXPORT_SYMBOL_GPL(pci_p2pdma_unmap_sg); > diff --git a/include/linux/memremap.h b/include/linux/memremap.h > index 9e907c338a44..1660f64ce96f 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_p2pdma_bus_offset; > }; > > #ifdef CONFIG_ZONE_DEVICE > diff --git a/include/linux/pci-p2pdma.h b/include/linux/pci-p2pdma.h > index c0dde3d3aac4..126eca697ab3 100644 > --- a/include/linux/pci-p2pdma.h > +++ b/include/linux/pci-p2pdma.h > @@ -36,6 +36,10 @@ 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_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents, > + enum dma_data_direction dir); > +void pci_p2pdma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, > + enum dma_data_direction dir); > #else /* CONFIG_PCI_P2PDMA */ > static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, > size_t size, u64 offset) > @@ -83,5 +87,14 @@ 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_p2pdma_map_sg(struct device *dev, > + struct scatterlist *sg, int nents, enum dma_data_direction dir) > +{ > + return 0; > +} > +static inline void pci_p2pdma_unmap_sg(struct device *dev, > + struct scatterlist *sg, int nents, enum dma_data_direction dir) > +{ > +} > #endif /* CONFIG_PCI_P2PDMA */ > #endif /* _LINUX_PCI_P2P_H */ > -- > 2.11.0 >
On 01/03/18 10:49 AM, Bjorn Helgaas wrote: >> +int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents, >> + enum dma_data_direction dir) > > Same question as before about why the mixture of "pci_*" interfaces > that take "struct device *" parameters. In this case, per the discussion in v1, it was felt the _map_sg() function should take the same arguments as dma_map_sg(). Logan
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index a57df78f6a32..4e1c81f64b29 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -188,6 +188,8 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size, pgmap->res.flags = pci_resource_flags(pdev, bar); pgmap->ref = &pdev->p2pdma->devmap_ref; pgmap->type = MEMORY_DEVICE_PCI_P2PDMA; + pgmap->pci_p2pdma_bus_offset = pci_bus_address(pdev, bar) - + pci_resource_start(pdev, bar); addr = devm_memremap_pages(&pdev->dev, pgmap); if (IS_ERR(addr)) @@ -616,3 +618,52 @@ void pci_p2pmem_publish(struct pci_dev *pdev, bool publish) pdev->p2pdma->published = publish; } EXPORT_SYMBOL_GPL(pci_p2pmem_publish); + +/* + * pci_p2pdma_map_sg - map a PCI peer-to-peer sg for DMA + * @dev: device doing the DMA request + * @sg: scatter list to map + * @nents: elements in the scatterlist + * @dir: DMA direction + * + * Returns the number of SG entries mapped + */ +int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ + struct dev_pagemap *pgmap; + struct scatterlist *s; + phys_addr_t paddr; + int i; + + /* + * p2pdma mappings are not compatible with devices that use + * dma_virt_ops. + */ + if (IS_ENABLED(CONFIG_DMA_VIRT_OPS) && dev->dma_ops == &dma_virt_ops) + return 0; + + for_each_sg(sg, s, nents, i) { + pgmap = sg_page(s)->pgmap; + paddr = sg_phys(s); + + s->dma_address = paddr - pgmap->pci_p2pdma_bus_offset; + sg_dma_len(s) = s->length; + } + + return nents; +} +EXPORT_SYMBOL_GPL(pci_p2pdma_map_sg); + +/** + * pci_p2pdma_unmap_sg - unmap a PCI peer-to-peer sg for DMA + * @dev: device doing the DMA request + * @sg: scatter list to map + * @nents: elements in the scatterlist + * @dir: DMA direction + */ +void pci_p2pdma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ +} +EXPORT_SYMBOL_GPL(pci_p2pdma_unmap_sg); diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 9e907c338a44..1660f64ce96f 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_p2pdma_bus_offset; }; #ifdef CONFIG_ZONE_DEVICE diff --git a/include/linux/pci-p2pdma.h b/include/linux/pci-p2pdma.h index c0dde3d3aac4..126eca697ab3 100644 --- a/include/linux/pci-p2pdma.h +++ b/include/linux/pci-p2pdma.h @@ -36,6 +36,10 @@ 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_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir); +void pci_p2pdma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, + enum dma_data_direction dir); #else /* CONFIG_PCI_P2PDMA */ static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size, u64 offset) @@ -83,5 +87,14 @@ 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_p2pdma_map_sg(struct device *dev, + struct scatterlist *sg, int nents, enum dma_data_direction dir) +{ + return 0; +} +static inline void pci_p2pdma_unmap_sg(struct device *dev, + struct scatterlist *sg, int nents, enum dma_data_direction dir) +{ +} #endif /* CONFIG_PCI_P2PDMA */ #endif /* _LINUX_PCI_P2P_H */
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 <logang@deltatee.com> --- drivers/pci/p2pdma.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/memremap.h | 1 + include/linux/pci-p2pdma.h | 13 ++++++++++++ 3 files changed, 65 insertions(+)