On Mon, May 10, 2021 at 11:03 PM Christoph Hellwig [off-list ref] wrote:

quoted

+static inline struct io_tlb_mem *get_io_tlb_mem(struct device *dev)
+{
+#ifdef CONFIG_DMA_RESTRICTED_POOL
+     if (dev && dev->dma_io_tlb_mem)
+             return dev->dma_io_tlb_mem;
+#endif /* CONFIG_DMA_RESTRICTED_POOL */
+
+     return io_tlb_default_mem;

Given that we're also looking into a not addressing restricted pool
I'd rather always assign the active pool to dev->dma_io_tlb_mem and
do away with this helper.

Where do you think is the proper place to do the assignment? First
time calling swiotlb_map? or in of_dma_configure_id?