[PATCH v5 3/4] arm,smmu: restructure code in preparation to new bindings support

[Stefano Stabellini <sstabellini@kernel.org>]

From: Brian Woods <brian.woods@xilinx.com>

Restructure some of the code and add supporting functions for adding
generic device tree (DT) binding support.  This will allow for using
current Linux device trees with just modifying the chosen field to
enable Xen.

Signed-off-by: Brian Woods <brian.woods@xilinx.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Rahul Singh <rahul.singh@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
---
 xen/drivers/passthrough/arm/smmu.c | 62 ++++++++++++++++--------------
 1 file changed, 34 insertions(+), 28 deletions(-)

diff --git a/xen/drivers/passthrough/arm/smmu.c b/xen/drivers/passthrough/arm/smmu.c
index 09773702c3..4aa3ecec57 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -812,53 +812,36 @@ static int insert_smmu_master(struct arm_smmu_device *smmu,
 	return 0;
 }
 
-static int register_smmu_master(struct arm_smmu_device *smmu,
-				struct device *dev,
-				struct of_phandle_args *masterspec)
+static int arm_smmu_dt_add_device_legacy(struct arm_smmu_device *smmu,
+					 struct device *dev,
+					 struct iommu_fwspec *fwspec)
 {
-	int i, ret = 0;
+	int i;
 	struct arm_smmu_master *master;
-	struct iommu_fwspec *fwspec;
+	struct device_node *dev_node = dev_get_dev_node(dev);
 
-	master = find_smmu_master(smmu, masterspec->np);
+	master = find_smmu_master(smmu, dev_node);
 	if (master) {
 		dev_err(dev,
 			"rejecting multiple registrations for master device %s\n",
-			masterspec->np->name);
+			dev_node->name);
 		return -EBUSY;
 	}
 
 	master = devm_kzalloc(dev, sizeof(*master), GFP_KERNEL);
 	if (!master)
 		return -ENOMEM;
-	master->of_node = masterspec->np;
-
-	ret = iommu_fwspec_init(&master->of_node->dev, smmu->dev);
-	if (ret) {
-		kfree(master);
-		return ret;
-	}
-
-	/* adding the ids here */
-	ret = iommu_fwspec_add_ids(&masterspec->np->dev,
-				   masterspec->args,
-				   masterspec->args_count);
-	if (ret)
-		return ret;
-
-	fwspec = dev_iommu_fwspec_get(dev);
+	master->of_node = dev_node;
 
 	/* Xen: Let Xen know that the device is protected by an SMMU */
-	dt_device_set_protected(masterspec->np);
+	dt_device_set_protected(dev_node);
 
 	for (i = 0; i < fwspec->num_ids; ++i) {
-		u16 streamid = masterspec->args[i];
-
 		if (!(smmu->features & ARM_SMMU_FEAT_STREAM_MATCH) &&
-		     (streamid >= smmu->num_mapping_groups)) {
+		     (fwspec->ids[i] >= smmu->num_mapping_groups)) {
 			dev_err(dev,
 				"stream ID for master device %s greater than maximum allowed (%d)\n",
-				masterspec->np->name, smmu->num_mapping_groups);
+				dev_node->name, smmu->num_mapping_groups);
 			return -ERANGE;
 		}
 		master->cfg.smendx[i] = INVALID_SMENDX;
@@ -866,6 +849,29 @@ static int register_smmu_master(struct arm_smmu_device *smmu,
 	return insert_smmu_master(smmu, master);
 }
 
+static int register_smmu_master(struct arm_smmu_device *smmu,
+				struct device *dev,
+				struct of_phandle_args *masterspec)
+{
+	int ret = 0;
+	struct iommu_fwspec *fwspec;
+
+	ret = iommu_fwspec_init(&masterspec->np->dev, smmu->dev);
+	if (ret)
+		return ret;
+
+	ret = iommu_fwspec_add_ids(&masterspec->np->dev,
+				   masterspec->args,
+				   masterspec->args_count);
+	if (ret)
+		return ret;
+
+	fwspec = dev_iommu_fwspec_get(&masterspec->np->dev);
+	return arm_smmu_dt_add_device_legacy(smmu,
+					     &masterspec->np->dev,
+					     fwspec);
+}
+
 static struct arm_smmu_device *find_smmu_for_device(struct device *dev)
 {
 	struct arm_smmu_device *smmu;
-- 
2.17.1