iommu/virtio: Sort reserved regions

To ease identity mapping support, keep the list of reserved regions
sorted.

Reviewed-by: Eric Auger <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Signed-off-by: Jean-Philippe Brucker <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>

Author: jpbrucker

drivers/iommu/virtio-iommu.c

@@ -423,7 +423,7 @@ static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
 	size_t size;
 	u64 start64, end64;
 	phys_addr_t start, end;
-	struct iommu_resv_region *region = NULL;
+	struct iommu_resv_region *region = NULL, *next;
 	unsigned long prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
 
 	start = start64 = le64_to_cpu(mem->start);
@@ -454,7 +454,12 @@ static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
 	if (!region)
 		return -ENOMEM;
 
-	list_add(&region->list, &vdev->resv_regions);
+	/* Keep the list sorted */
+	list_for_each_entry(next, &vdev->resv_regions, list) {
+		if (next->start > region->start)
+			break;
+	}
+	list_add_tail(&region->list, &next->list);
 	return 0;
 }