iommu/dma: Fix IOVA reserve dma ranges

BugLink: https://bugs.launchpad.net/bugs/1938199

[ Upstream commit 571f316 ]

Fix IOVA reserve failure in the case when address of first memory region
listed in dma-ranges is equal to 0x0.

Fixes: aadad09 ("iommu/dma: Reserve IOVA for PCIe inaccessible DMA address")
Signed-off-by: Srinath Mannam <[email protected]>
Reviewed-by: Robin Murphy <[email protected]>
Tested-by: Sven Peter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
Signed-off-by: Stefan Bader <[email protected]>

Author: mannams

drivers/iommu/dma-iommu.c

@@ -216,9 +216,11 @@ static int iova_reserve_pci_windows(struct pci_dev *dev,
 			lo = iova_pfn(iovad, start);
 			hi = iova_pfn(iovad, end);
 			reserve_iova(iovad, lo, hi);
-		} else {
+		} else if (end < start) {
 			/* dma_ranges list should be sorted */
-			dev_err(&dev->dev, "Failed to reserve IOVA\n");
+			dev_err(&dev->dev,
+				"Failed to reserve IOVA [%#010llx-%#010llx]\n",
+				start, end);
 			return -EINVAL;
 		}