4 files changed, 64 insertions, 13 deletions

diff --git a/drivers/acpi/acpi_watchdog.c b/drivers/acpi/acpi_watchdog.c
index bf22c29d2517..11b113f8e367 100644
--- a/drivers/acpi/acpi_watchdog.c
+++ b/drivers/acpi/acpi_watchdog.c
@@ -66,7 +66,7 @@ void __init acpi_watchdog_init(void)
 	for (i = 0; i < wdat->entries; i++) {
 		const struct acpi_generic_address *gas;
 		struct resource_entry *rentry;
-		struct resource res;
+		struct resource res = {};
 		bool found;
 
 		gas = &entries[i].register_region;
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 077f9bad6f44..3c3a37b8503b 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -743,17 +743,19 @@ static int ghes_proc(struct ghes *ghes)
 	}
 	ghes_do_proc(ghes, ghes->estatus);
 
+out:
+	ghes_clear_estatus(ghes);
+
+	if (rc == -ENOENT)
+		return rc;
+
 	/*
 	 * GHESv2 type HEST entries introduce support for error acknowledgment,
 	 * so only acknowledge the error if this support is present.
 	 */
-	if (is_hest_type_generic_v2(ghes)) {
-		rc = ghes_ack_error(ghes->generic_v2);
-		if (rc)
-			return rc;
-	}
-out:
-	ghes_clear_estatus(ghes);
+	if (is_hest_type_generic_v2(ghes))
+		return ghes_ack_error(ghes->generic_v2);
+
 	return rc;
 }
 
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 9565d572f8dd..de56394dd161 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1178,12 +1178,44 @@ dev_put:
 	return ret;
 }
 
+static bool __init iort_enable_acs(struct acpi_iort_node *iort_node)
+{
+	if (iort_node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
+		struct acpi_iort_node *parent;
+		struct acpi_iort_id_mapping *map;
+		int i;
+
+		map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, iort_node,
+				   iort_node->mapping_offset);
+
+		for (i = 0; i < iort_node->mapping_count; i++, map++) {
+			if (!map->output_reference)
+				continue;
+
+			parent = ACPI_ADD_PTR(struct acpi_iort_node,
+					iort_table,  map->output_reference);
+			/*
+			 * If we detect a RC->SMMU mapping, make sure
+			 * we enable ACS on the system.
+			 */
+			if ((parent->type == ACPI_IORT_NODE_SMMU) ||
+				(parent->type == ACPI_IORT_NODE_SMMU_V3)) {
+				pci_request_acs();
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
 static void __init iort_init_platform_devices(void)
 {
 	struct acpi_iort_node *iort_node, *iort_end;
 	struct acpi_table_iort *iort;
 	struct fwnode_handle *fwnode;
 	int i, ret;
+	bool acs_enabled = false;
 
 	/*
 	 * iort_table and iort both point to the start of IORT table, but
@@ -1203,6 +1235,9 @@ static void __init iort_init_platform_devices(void)
 			return;
 		}
 
+		if (!acs_enabled)
+			acs_enabled = iort_enable_acs(iort_node);
+
 		if ((iort_node->type == ACPI_IORT_NODE_SMMU) ||
 			(iort_node->type == ACPI_IORT_NODE_SMMU_V3)) {
 
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index c1c216163de3..3fb8ff513461 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -908,11 +908,12 @@ struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
 					    struct fwnode_handle *child)
 {
 	const struct acpi_device *adev = to_acpi_device_node(fwnode);
-	struct acpi_device *child_adev = NULL;
 	const struct list_head *head;
 	struct list_head *next;
 
 	if (!child || is_acpi_device_node(child)) {
+		struct acpi_device *child_adev;
+
 		if (adev)
 			head = &adev->children;
 		else
@@ -922,8 +923,8 @@ struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
 			goto nondev;
 
 		if (child) {
-			child_adev = to_acpi_device_node(child);
-			next = child_adev->node.next;
+			adev = to_acpi_device_node(child);
+			next = adev->node.next;
 			if (next == head) {
 				child = NULL;
 				goto nondev;
@@ -941,8 +942,8 @@ struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
 		const struct acpi_data_node *data = to_acpi_data_node(fwnode);
 		struct acpi_data_node *dn;
 
-		if (child_adev)
-			head = &child_adev->data.subnodes;
+		if (adev)
+			head = &adev->data.subnodes;
 		else if (data)
 			head = &data->data.subnodes;
 		else
@@ -1293,3 +1294,16 @@ static int acpi_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
 DECLARE_ACPI_FWNODE_OPS(acpi_device_fwnode_ops);
 DECLARE_ACPI_FWNODE_OPS(acpi_data_fwnode_ops);
 const struct fwnode_operations acpi_static_fwnode_ops;
+
+bool is_acpi_device_node(const struct fwnode_handle *fwnode)
+{
+	return !IS_ERR_OR_NULL(fwnode) &&
+		fwnode->ops == &acpi_device_fwnode_ops;
+}
+EXPORT_SYMBOL(is_acpi_device_node);
+
+bool is_acpi_data_node(const struct fwnode_handle *fwnode)
+{
+	return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &acpi_data_fwnode_ops;
+}
+EXPORT_SYMBOL(is_acpi_data_node);