Since we're touching this code, it might be a good opportunity to fix
the old typo
+ * dma_iova_link - Link a range of IOVA space
+ * @dev: DMA device
+ * @state: IOVA state
+ * @phys: physical address to link
+ * @offset: offset into the IOVA state to map into
+ * @size: size of the buffer
+ * @dir: DMA direction
+ * @attrs: attributes of mapping properties
+ *
+ * Link a range of IOVA space for the given IOVA state without IOTLB sync.
+ * This function is used to link multiple physical addresses in contigueous
old typo contigueous -> contiguous
+ * IOVA space without performing costly IOTLB sync.
+ *
+ * The caller is responsible to call to dma_iova_sync() to sync IOTLB at
+ * the end of linkage.
+ */
+int dma_iova_link(struct device *dev, struct dma_iova_state *state,
+ phys_addr_t phys, size_t offset, size_t size,
+ enum dma_data_direction dir, unsigned long attrs)
+{
+ struct iommu_domain *domain = iommu_get_dma_domain(dev);
+ struct iommu_dma_cookie *cookie = domain->iova_cookie;
+ struct iova_domain *iovad = &cookie->iovad;
+ size_t iova_start_pad = iova_offset(iovad, phys);
+
+ if (WARN_ON_ONCE(iova_start_pad && offset > 0))
+ return -EIO;
+
+ if (dev_use_swiotlb(dev, size, dir) && iova_offset(iovad, phys | size))
+ return iommu_dma_iova_link_swiotlb(dev, state, phys, offset,
+ size, dir, attrs);
+
+ return __dma_iova_link(dev, state->addr + offset - iova_start_pad,
+ phys - iova_start_pad,
+ iova_align(iovad, size + iova_start_pad), dir, attrs);
+}
+EXPORT_SYMBOL_GPL(dma_iova_link);
+
+/**
+ * dma_iova_sync - Sync IOTLB
+ * @dev: DMA device
+ * @state: IOVA state
+ * @offset: offset into the IOVA state to sync
+ * @size: size of the buffer
+ *
+ * Sync IOTLB for the given IOVA state. This function should be called on
+ * the IOVA-contigous range created by one ore more dma_iova_link() calls
old typo IOVA-contigous -> IOVA-contiguous
+ * to sync the IOTLB.
+ */
+int dma_iova_sync(struct device *dev, struct dma_iova_state *state,
+ size_t offset, size_t size)
+{
+ struct iommu_domain *domain = iommu_get_dma_domain(dev);
+ struct iommu_dma_cookie *cookie = domain->iova_cookie;
+ struct iova_domain *iovad = &cookie->iovad;
+ dma_addr_t addr = state->addr + offset;
+ size_t iova_start_pad = iova_offset(iovad, addr);
+
+ return iommu_sync_map(domain, addr - iova_start_pad,
+ iova_align(iovad, size + iova_start_pad));
+}
Thanks,
Alok
