From: Will Davis <[email protected]> Add functions to DMA-map and -unmap a resource for a given device. This will allow devices to DMA-map a peer device's resource (for example, another device's BAR region on PCI) to enable peer-to-peer transactions.
Signed-off-by: Will Davis <[email protected]> Reviewed-by: Terence Ripperda <[email protected]> Reviewed-by: John Hubbard <[email protected]> --- include/asm-generic/dma-mapping-broken.h | 9 +++++++++ include/asm-generic/dma-mapping-common.h | 34 ++++++++++++++++++++++++++++++++ include/linux/dma-mapping.h | 7 +++++++ 3 files changed, 50 insertions(+) diff --git a/include/asm-generic/dma-mapping-broken.h b/include/asm-generic/dma-mapping-broken.h index 6c32af9..d171f01 100644 --- a/include/asm-generic/dma-mapping-broken.h +++ b/include/asm-generic/dma-mapping-broken.h @@ -59,6 +59,15 @@ extern void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size, enum dma_data_direction direction); +extern dma_addr_t +dma_map_resource(struct device *dev, struct resource *res, + unsigned long offset, size_t size, + enum dma_data_direction direction); + +extern void +dma_unmap_resource(struct device *dev, dma_addr_t dma_address, size_t size, + enum dma_data_direction direction); + extern void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction); diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h index 940d5ec..cd9948d 100644 --- a/include/asm-generic/dma-mapping-common.h +++ b/include/asm-generic/dma-mapping-common.h @@ -73,6 +73,36 @@ static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg ops->unmap_sg(dev, sg, nents, dir, attrs); } +static inline dma_addr_t dma_map_resource_attrs(struct device *dev, + struct resource *res, + size_t offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + dma_addr_t addr = 0; + + BUG_ON(!valid_dma_direction(dir)); + if (ops->map_resource) + addr = ops->map_resource(dev, res, offset, size, dir, attrs); + debug_dma_map_resource(dev, res, offset, size, dir, addr); + + return addr; +} + +static inline void dma_unmap_resource_attrs(struct device *dev, dma_addr_t addr, + size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + + BUG_ON(!valid_dma_direction(dir)); + if (ops->unmap_resource) + ops->unmap_resource(dev, addr, size, dir, attrs); + debug_dma_unmap_resource(dev, addr, size, dir); +} + static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, size_t offset, size_t size, enum dma_data_direction dir) @@ -180,6 +210,10 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, #define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, NULL) #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, NULL) #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, NULL) +#define dma_map_resource(d, e, o, s, r) \ + dma_map_resource_attrs(d, e, o, s, r, NULL) +#define dma_unmap_resource(d, a, s, r) \ + dma_unmap_resource_attrs(d, a, s, r, NULL) extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size); diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index ac07ff0..05b0b51 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -34,6 +34,13 @@ struct dma_map_ops { void (*unmap_page)(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs); + dma_addr_t (*map_resource)(struct device *dev, struct resource *res, + unsigned long offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs); + void (*unmap_resource)(struct device *dev, dma_addr_t dma_handle, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs); /* * map_sg returns 0 on error and a value > 0 on success. * It should never return a value < 0. -- 2.4.0 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
