On 2024/10/27 22:21, Leon Romanovsky wrote:
+/**
+ * dma_iova_sync - Sync IOTLB
+ * @dev: DMA device
+ * @state: IOVA state
+ * @offset: offset into the IOVA state to sync
+ * @size: size of the buffer
+ * @ret: return value from the last IOVA operation
+ *
+ * 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
+ * to sync the IOTLB.
+ */
+int dma_iova_sync(struct device *dev, struct dma_iova_state *state,
+ size_t offset, size_t size, int ret)
+{
+ 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);
+
+ addr -= iova_start_pad;
+ size = iova_align(iovad, size + iova_start_pad);
+
+ if (!ret)
+ ret = iommu_sync_map(domain, addr, size);
+ if (ret)
+ iommu_unmap(domain, addr, size);
It appears strange that mapping is not done in this helper, but
unmapping is added in the failure path. Perhaps I overlooked anything?
To my understanding, it should like below:
return iommu_sync_map(domain, addr, size);
In the drivers that make use of this interface should do something like
below:
ret = dma_iova_sync(...);
if (ret)
dma_iova_destroy(...)
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dma_iova_sync);
Thanks,
baolu
