On Wed, Jan 10, 2018 at 12:22:18PM +0000, Robin Murphy wrote:

quoted

+	if (phys_addr == SWIOTLB_MAP_ERROR)
+		goto out_warn;
  -		/* Confirm address can be DMA'd by device */
-		if (dev_addr + size - 1 > dma_mask) {
-			printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
-			       (unsigned long long)dma_mask,
-			       (unsigned long long)dev_addr);
+	*dma_handle = swiotlb_phys_to_dma(dev, phys_addr);

nit: this should probably go after the dma_coherent_ok() check (as with the 
original logic).

But the originall logic also needs the dma_addr_t for the
dma_coherent_ok check:

		dev_addr = swiotlb_phys_to_dma(hwdev, paddr);
		/* Confirm address can be DMA'd by device */
		if (dev_addr + size - 1 > dma_mask) {
			...
			goto err_warn;
		}

or do you mean assining to *dma_handle?  The dma_handle is not
valid for a failure return, so I don't think this should matter.

quoted

+	if (ret) {
+		*dma_handle = swiotlb_virt_to_bus(hwdev, ret);
+		if (dma_coherent_ok(hwdev, *dma_handle, size)) {
+			memset(ret, 0, size);
+			return ret;
+		}

Aren't we leaking the pages here?

Yes, that free_pages got lost somewhere in the rebases, I've added
it back.