From: Jean-Philippe Brucker <jean-philippe@linaro.org>
Date: Wed, 1 Dec 2021 17:33:23 +0000
Subject: iommu/virtio: Sort reserved regions
Git-commit: 5610979415649f3743a7c3de03ab46c9a3bfff16
Patch-mainline: v5.17-rc1
References: bsc#1205701

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

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20211201173323.1045819-4-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/virtio-iommu.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index 14dfee76fd19..1b3c1f2741c6 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/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;
 }