Merge: iommu/arm-smmu-v3: Backport fix for duplicate stream ID warnings

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/6896

JIRA: https://issues.redhat.com/browse/RHEL-89787

iommu/arm-smmu-v3: Backport fix for duplicate stream ID warnings

Backport commit b00d249 ("iommu/arm-smmu-v3: Fix iommu_device_probe bug...")
to resolve SMMUv3 probe failures caused by duplicate stream IDs in ASPEED PCI
topologies. This fixes "stream N already in tree" warnings during device probe
and prevents IOMMU configuration errors.

Testing on Ampere AltraMax (aarch64) confirmed elimination of duplicate stream
ID warnings. Also, no soft lock-ups were observed in AST driver.

Signed-off-by: Steve Dunnagan <sdunnaga@redhat.com>

Approved-by: Jerry Snitselaar <jsnitsel@redhat.com>
Approved-by: Eder Zulian <ezulian@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Augusto Caringi <acaringi@redhat.com>

Author: caringi

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

@@ -3364,6 +3364,7 @@ static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
 	mutex_lock(&smmu->streams_mutex);
 	for (i = 0; i < fwspec->num_ids; i++) {
 		struct arm_smmu_stream *new_stream = &master->streams[i];
+		struct rb_node *existing;
 		u32 sid = fwspec->ids[i];
 
 		new_stream->id = sid;
@@ -3374,10 +3375,20 @@ static int arm_smmu_insert_master(struct arm_smmu_device *smmu,
 			break;
 
 		/* Insert into SID tree */
-		if (rb_find_add(&new_stream->node, &smmu->streams,
-				arm_smmu_streams_cmp_node)) {
-			dev_warn(master->dev, "stream %u already in tree\n",
-				 sid);
+		existing = rb_find_add(&new_stream->node, &smmu->streams,
+				       arm_smmu_streams_cmp_node);
+		if (existing) {
+			struct arm_smmu_master *existing_master =
+				rb_entry(existing, struct arm_smmu_stream, node)
+					->master;
+
+			/* Bridged PCI devices may end up with duplicated IDs */
+			if (existing_master == master)
+				continue;
+
+			dev_warn(master->dev,
+				 "stream %u already in tree from dev %s\n", sid,
+				 dev_name(existing_master->dev));
 			ret = -EINVAL;
 			break;
 		}