Add methods to map/unmap device resources addresses for dma_map_ops that are IOMMU aware. This is needed to map a device MMIO register from a physical address.
Signed-off-by: Niklas Söderlund <niklas.soderlund+rene...@ragnatech.se> --- arch/arm/mm/dma-mapping.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 0eca381..ae2b175 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1814,6 +1814,63 @@ static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle, __free_iova(mapping, iova, len); } +/** + * arm_iommu_map_resource - map a device resource for DMA + * @dev: valid struct device pointer + * @phys_addr: physical address of resource + * @size: size of resource to map + * @dir: DMA transfer direction + */ +static dma_addr_t arm_iommu_map_resource(struct device *dev, + phys_addr_t phys_addr, size_t size, + enum dma_data_direction dir, struct dma_attrs *attrs) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + dma_addr_t dma_addr; + int ret, prot; + phys_addr_t addr = phys_addr & PAGE_MASK; + int offset = phys_addr & ~PAGE_MASK; + int len = PAGE_ALIGN(size + offset); + + dma_addr = __alloc_iova(mapping, size); + if (dma_addr == DMA_ERROR_CODE) + return dma_addr; + + prot = __dma_direction_to_prot(dir) | IOMMU_MMIO; + + ret = iommu_map(mapping->domain, dma_addr, addr, len, prot); + if (ret < 0) + goto fail; + + return dma_addr + offset; +fail: + __free_iova(mapping, dma_addr, size); + return DMA_ERROR_CODE; +} + +/** + * arm_iommu_unmap_resource - unmap a device DMA resource + * @dev: valid struct device pointer + * @dma_handle: DMA address to resource + * @size: size of resource to map + * @dir: DMA transfer direction + */ +static void arm_iommu_unmap_resource(struct device *dev, dma_addr_t dma_handle, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + dma_addr_t iova = dma_handle & PAGE_MASK; + int offset = dma_handle & ~PAGE_MASK; + int len = PAGE_ALIGN(size + offset); + + if (!iova) + return; + + iommu_unmap(mapping->domain, iova, len); + __free_iova(mapping, iova, len); +} + static void arm_iommu_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { @@ -1858,6 +1915,9 @@ struct dma_map_ops iommu_ops = { .sync_sg_for_cpu = arm_iommu_sync_sg_for_cpu, .sync_sg_for_device = arm_iommu_sync_sg_for_device, + .map_resource = arm_iommu_map_resource, + .unmap_resource = arm_iommu_unmap_resource, + .set_dma_mask = arm_dma_set_mask, }; @@ -1873,6 +1933,9 @@ struct dma_map_ops iommu_coherent_ops = { .map_sg = arm_coherent_iommu_map_sg, .unmap_sg = arm_coherent_iommu_unmap_sg, + .map_resource = arm_iommu_map_resource, + .unmap_resource = arm_iommu_unmap_resource, + .set_dma_mask = arm_dma_set_mask, }; -- 2.7.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu